JP2008191741A - Method for simulating generation of air receiver in object to be dipped process and computer-executable program for executing this simulation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately simulate air receivers generated in an object to be dipped process even for the object to be dipped having a connection to which a plurality of members are connected. <P>SOLUTION: The attributes of triangular meshes are set by analyzing adjacent meshes that are adjacent in sequence from a free edge mesh that forms the object to be dipped 30. This analysis process is finished when it reaches the setting of the attributes of the triangular meshes forming the multiple edge (ME) of the object to be dipped 30. Thus, different meshes can be set for the triangular meshes on one side and the other side of the multiple edge (ME), and air receivers in the object to be dipped 30 having the multiple edge (ME) can be quickly and accurately simulated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an air pool generation simulation method for an object to be immersed that simulates an air pool generated in an object to be immersed when immersed in a paint tank, and a program executable by a computer that executes the simulation method.

  An object to be dipped such as a vehicle body of a vehicle is dipped in a paint tank filled with a liquid paint so that the surface thereof is electrodeposited. According to such a coating method, the thickness of the coating film formed on the surface of the object to be immersed can be made substantially uniform, or a similar coating process can be applied to the welded portion of the object to be immersed. There are advantages such as. On the other hand, for example, in the case of a vehicle body, a plurality of concave portions are formed on the inner surface of the hood, the inner surface of the roof, the lower surface of the floor, etc., so that the concave portion becomes an air pocket called an air pocket. In the state where the air in the air pool remains, there is a drawback that the portion cannot be painted.

  Therefore, for example, as shown in Patent Document 1, a discharge path for discharging air into the atmosphere is formed in advance in the object to be immersed so as not to cause air accumulation in the object to be immersed. Air is discharged into the atmosphere through a discharge path so that the entire surface of the object to be immersed can be subjected to a coating process.

  In general, the air pool generated in the object to be immersed can be simulated by using a well-known analysis method using a free surface, and the simulation result is reflected in the design of the object to be immersed. Work efficiency can be improved. The present applicant has applied for the simulation methods shown in Japanese Patent Application Nos. 2006-180453 and 2005-330098 in order to shorten the time required for the simulation and further improve the efficiency of the design work.

Among the simulation methods, the former (Japanese Patent Application No. 2006-180453) divides the numerical calculation model of the object to be immersed into two-dimensional elements without dividing them into three-dimensional elements. The generation of air pockets is simulated using a numerical calculation model of the object to be immersed formed. The latter (Japanese Patent Application No. 2005-330098) generates a numerical calculation model by arranging a plurality of nodes on the surface of the object to be immersed, and simulates the occurrence of air pockets using the coordinate data of each node. ing. In both the former and the latter cases, the load on the computer is reduced by using the data forming the two-dimensional elements and the coordinate data of the nodes, and as a result, the time required for the simulation can be shortened. .
Japanese Patent Laid-Open No. 10-045037

  However, according to each simulation method described above, since the occurrence of air pools is simulated for each of the plurality of members forming the object to be immersed, the object to be immersed formed by connecting the plurality of members. It was not possible to obtain accurate simulation results for.

  In other words, for example, an object to be dipped formed by connecting the ends of a pair of members so that the cross section has a square shape (saddle shape), the opening side of the square shape is directed downward. However, according to the simulation methods described above, any of the members is erroneously determined as “no air retention”. Could cause problems.

  An object of the present invention is to provide an air pool in an object to be immersed that can accurately simulate an air pool generated in the object to be immersed, even if the object to be immersed has a connection portion to which a plurality of members are connected. It is an object to provide a generation simulation method and a program executable by a computer that executes the simulation method.

  The method for simulating the occurrence of air stagnation in an object to be immersed in the present invention is a method for simulating the occurrence of air stagnation in an object to be immersed in the object to be processed for simulating the air stagnation generated in the object to be immersed in immersion in the paint tank. A first step of dividing the shape data of the object to be immersed having a connection part to which a member is connected into a plurality of two-dimensional elements and setting an attribute of each element to air; A second step of setting an element that forms an end or a hole of the object to be immersed as an initial boundary element and setting an attribute of the initial boundary element to paint, and an element that shares a node with the initial boundary element A third step of setting an adjacent element, and analyzing the adjacent element set in the third step using the initial boundary element, and based on the analysis result The fourth step of setting the attribute of the adjacent element, the adjacent element that has been analyzed in the fourth step is set as a secondary boundary element, and an element sharing a node with this secondary boundary element is set as an adjacent element And a fifth step of analyzing the adjacent element set in the fifth step using the secondary boundary element, and setting an attribute of the adjacent element based on the analysis result And determining whether an adjacent element adjacent to the secondary boundary element is an element of the connection part, and determining that an adjacent element adjacent to the secondary boundary element is not an element of the connection part Until the adjacent element adjacent to the secondary boundary element is determined to be an element of the connecting portion, the processing of each step is repeated in the order of the fifth step and the sixth step, element If it is determined that the element of the connection part is characterized by having a seventh step of terminating the analysis.

  In the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention, in the fourth step and the sixth step, the initial boundary element, the secondary boundary element, and the adjacent element are set to the center of gravity of each element. If the height of the centroid of the initial boundary element or the secondary boundary element whose attribute is paint is compared with the height of the centroid of the adjacent element by comparing the height of the point, the attribute of the adjacent element If the height of the centroid of the initial boundary element or the secondary boundary element whose attribute is the paint is lower than the height of the centroid of the adjacent element, the attribute of the adjacent element is It is characterized by determining that it is air.

  In the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention, in the fourth step and the sixth step, the initial boundary element, the secondary boundary element, and the adjacent element are set to the highest of the respective elements. Compare the height of either one of the nodes or the lowest nodes, the height of the node of the initial boundary element or the secondary boundary element attributed as paint is higher than the height of the node of the adjacent element If it is higher, it is determined that the attribute of the adjacent element is paint, and if the height of the node of the initial boundary element or the secondary boundary element whose attribute is paint is lower than the height of the node of the adjacent element It is determined that the attribute of the adjacent element is air.

  In addition to the seventh step, the method for simulating the occurrence of air accumulation in an object to be immersed according to the present invention includes the step of determining whether an attribute of one element among the elements sharing the node of the connection portion is air. The ninth step of setting the attribute of the element to paint when the attribute of one element is determined to be air in the eighth step, and the attribute to paint in the ninth step. Performing the tenth step of setting the set element as an initial boundary element, and returning to the third step based on the initial boundary element set in the tenth step for analysis processing .

  In the fourth step that is performed after returning to the third step, the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention is characterized in that the attribute of the adjacent element adjacent to the initial boundary element is air. If it is determined, the attribute of the initial boundary element is returned to air and the analysis is terminated.

  The method for simulating the occurrence of air stagnation in an object to be immersed in the present invention is a method for simulating the occurrence of air stagnation in an object to be immersed in the object to be processed for simulating the air stagnation generated in the object to be immersed in immersion in the paint tank. A first step of disposing a plurality of nodes on the surface of the shape data of the object to be immersed having a connection part to which a member is connected, and setting an attribute of each node to air; and among the nodes, the object to be immersed A second step of setting the node forming the end or hole of the workpiece as an initial node, and setting the attribute of the initial node as paint, and a node adjacent to the initial node as an adjacent node Analyzing the adjacent node set in the third step and the third step using the initial node, and determining the attribute of the adjacent node based on the analysis result And a fifth step of setting the adjacent node analyzed in the fourth step as a secondary node, and setting a node adjacent to the secondary node as an adjacent node. Analyzing the adjacent node set in the fifth step using the secondary node, and setting the attribute of the adjacent node based on the analysis result; and adjoining the secondary node It is determined whether or not an adjacent node in the relationship is a node of the connection part, and when it is determined that an adjacent node adjacent to the secondary node is not a node of the connection part, the secondary node and The process of each step is repeated in the order of the fifth step and the sixth step until it is determined that the adjacent node in the adjacent relationship is the node of the connection unit, and the secondary node is the node of the connection unit Determined to be It is characterized by having a seventh step of terminating the analysis if.

  In the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention, in the fourth step and the sixth step, the heights of the initial node, the secondary node and the adjacent node are compared. When the height of the initial node or the secondary node whose attribute is paint is higher than the height of the adjacent node, it is determined that the attribute of the adjacent node is paint, and the attribute is paint When the height of the initial node or the secondary node is lower than the height of the adjacent node, it is determined that the attribute of the adjacent node is air.

  In addition to the seventh step, the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention extracts a pair of adjacent nodes in the connecting portion, selects the closest node from each node, and An eighth step of determining whether one of the neighboring nodes has an attribute of air or whether all of the neighboring nodes have an attribute of paint; and one proximity in the eighth step. When it is determined that the attribute of the node is air, or the attributes of all adjacent nodes are paints, the attribute is set to paint the attributes of the adjacent nodes of air and the pair of nodes at the connection portion. And a tenth step of setting the adjacent node whose attribute is set to paint in the ninth step as an initial node, and performing the tenth step. Wherein the analyzing process returns to the third step based on the initial node set in.

  In the fourth step that is executed after returning to the third step, the method for simulating the occurrence of air accumulation in the object to be submerged according to the present invention is characterized in that the attribute of the adjacent node adjacent to the initial node is air. If it is determined that there is, the attribute of the initial node and the pair of nodes is returned to the air, and the analysis is terminated.

  In the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention, in the first step, a two-dimensional element formed by a pair of adjacent nodes in the connection portion is generated, and the attribute of the element is changed to air. In the seventh step, it is determined whether or not the secondary node forms an element of the connection portion generated in the first step.

  In the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention, in the first step, the nodes forming the connection portion are given sub-attributes corresponding to the number of adjacent nodes adjacent to the node. In the sixth step, each of the sub-attributes is set in accordance with the attribute on the secondary node side to be compared.

  In the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention, the object to be immersed is a vehicle body.

  The computer-executable program for executing the method for simulating the occurrence of air stagnation in the object to be immersed according to the present invention is an air stagnation in the object to be immersed that simulates the air stagnation generated in the object to be immersed when immersed in the paint tank. A computer-executable program for executing the generation simulation method, wherein the shape data of the object to be immersed having a connection portion to which a plurality of members are connected is divided into a plurality of two-dimensional elements, The first step of setting the attribute to air, and the element that forms the end or hole of the object to be dipped among the elements is set as the initial boundary element, and the attribute of the initial boundary element is set as the paint A third step of setting an element sharing a node with the initial boundary element as an adjacent element, and a third step of Analyzing the adjacent element set in step 4 using the initial boundary element, and setting the attribute of the adjacent element based on the analysis result; and the adjacent step in which the analysis is completed in the fourth step A fifth step of setting an element as a secondary boundary element, and setting an element sharing a node with the secondary boundary element as an adjacent element; and the adjacent element set in the fifth step as the secondary boundary A sixth step of analyzing using an element, and setting an attribute of the adjacent element based on the analysis result, and determining whether an adjacent element adjacent to the secondary boundary element is an element of the connection portion If it is determined that the adjacent element adjacent to the secondary boundary element is not an element of the connection part, the adjacent element adjacent to the secondary boundary element is determined to be the element of the connection part until the determination is made. First And a sixth step of ending the analysis when the secondary boundary element is determined to be an element of the connecting portion. Features.

  In the fourth step and the sixth step, a program that can be executed by a computer that executes the method for simulating the occurrence of air stagnation in an object to be immersed according to the present invention includes the initial boundary element, the secondary boundary element, and the Compare the height of the center of gravity of each element with the adjacent element, and the height of the center of gravity of the initial boundary element or the secondary boundary element whose attribute is the paint is higher than the height of the center of gravity of the adjacent element. Is higher, the attribute of the adjacent element is determined to be paint, and the height of the centroid of the initial boundary element or the secondary boundary element whose attribute is paint is higher than the height of the centroid of the adjacent element. When the value is low, it is determined that the attribute of the adjacent element is air.

  In the fourth step and the sixth step, a program that can be executed by a computer that executes the method for simulating the occurrence of air stagnation in an object to be immersed according to the present invention includes the initial boundary element, the secondary boundary element, and the The height of either the highest node or the lowest node of each element is compared with the adjacent elements, and the height of the node of the initial boundary element or the secondary boundary element whose attribute is paint is determined. When the height of the node of the adjacent element is higher than that of the adjacent element, the attribute of the adjacent element is determined to be paint, and the height of the node of the initial boundary element or the secondary boundary element having the attribute of paint is the adjacent element If it is lower than the height of the node, it is determined that the attribute of the adjacent element is air.

  In addition to the seventh step, a computer-executable program for executing the method for simulating the occurrence of air accumulation in an object to be immersed according to the present invention has an attribute of one element among the elements sharing the node of the connection portion. An eighth step for determining whether or not the element is, a ninth step for setting the attribute of the element in the paint when the attribute of one element is determined to be air in the eighth step, A tenth step of setting an element whose attribute is set to paint in the ninth step as an initial boundary element, and returning to the third step based on the initial boundary element set in the tenth step Analysis processing.

  The computer-executable program for executing the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention is adjacent to the initial boundary element in the fourth step executed after returning to the third step. When it is determined that the attribute of the adjacent element is air, the attribute of the initial boundary element is returned to air and the analysis is terminated.

  The computer-executable program for executing the method for simulating the occurrence of air stagnation in the object to be immersed according to the present invention is an air stagnation in the object to be immersed that simulates the air stagnation generated in the object to be immersed when immersed in the paint tank. A computer-executable program for executing the generation simulation method, wherein a plurality of nodes are arranged on the surface of the shape data of the object to be immersed having a connection part to which a plurality of members are connected, and attributes of the nodes are set. A first step of setting to air; and a second node that sets an end node or a hole portion of the object to be immersed among the nodes to be an initial node and sets an attribute of the initial node to paint A step, a third step of setting a node adjacent to the initial node as an adjacent node, and a setting in the third step. A fourth step of analyzing the adjacent node using the initial node, and setting an attribute of the adjacent node based on the analysis result; and the adjacent node analyzed in the fourth step as a secondary node. A fifth step of setting a node and setting a node adjacent to the secondary node as an adjacent node, and analyzing the adjacent node set in the fifth step using the secondary node, A sixth step of setting an attribute of the adjacent node based on the analysis result; and determining whether an adjacent node adjacent to the secondary node is a node of the connection portion; and the secondary node If it is determined that the adjacent node adjacent to the secondary node is not a node of the connection unit, the fifth step is performed until it is determined that the adjacent node adjacent to the secondary node is the node of the connection unit. And the sixth Was repeated processing in each step in order of step, when the secondary node is determined to be the node of the connection part is characterized by having a seventh step of terminating the analysis.

  The computer-executable program for executing the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention includes the initial node, the secondary node, and the adjacent node in the fourth step and the sixth step. If the height of the initial node or the secondary node whose attribute is a paint is higher than the height of the adjacent node, it is determined that the attribute of the adjacent node is a paint. If the height of the initial node or the secondary node whose attribute is paint is lower than the height of the adjacent node, it is determined that the attribute of the adjacent node is air.

  In addition to the seventh step, a computer-executable program for executing the method for simulating the occurrence of air stagnation in an object to be immersed according to the present invention extracts a pair of adjacent nodes at the connection portion, and extracts the most from each of the nodes. An eighth step of selecting adjacent neighboring nodes and determining whether an attribute of one of the neighboring nodes is air or whether an attribute of all the neighboring nodes is paint; In the eighth step, when it is determined that the attribute of one adjacent node is air, or when it is determined that the attributes of all the adjacent nodes are paints, a pair of attributes in the adjacent node of air and the connection portion A ninth step of setting the attribute of the node to paint, and a first step of setting the adjacent node whose attribute is set to paint in the ninth step as an initial node Perform a 0 in steps, characterized in that the analysis process returns to the third step based on the initial node set in the tenth step.

  The computer-executable program for executing the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention has an adjacent relationship with the initial node in the fourth step executed after returning to the third step. When it is determined that the attribute of the certain adjacent node is air, the attributes of the initial node and the pair of nodes are returned to air, and the analysis is terminated.

  The computer-executable program for executing the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention generates, in the first step, a two-dimensional element formed by a pair of adjacent nodes in the connection portion. Then, the attribute of the element is set to air, and in the seventh step, it is determined whether or not the secondary node forms the element of the connection portion generated in the first step. To do.

  The computer-executable program for executing the method for simulating the occurrence of air stagnation in the object to be immersed according to the present invention includes, in the first step, a node that is adjacent to the node at the node forming the connection portion. Sub-attributes corresponding to numbers are provided, and in the sixth step, the sub-attributes are set in accordance with the secondary node side attributes to be compared.

  The computer-executable program for executing the simulation method for generating air stagnation in the object to be immersed according to the present invention is characterized in that the object to be immersed is a vehicle body.

  According to the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention, the shape data of the object to be immersed is formed by two-dimensional elements (or arrangement of nodes), and the attributes of these elements (nodes) are set. It sets by analyzing the elements (nodes) that are adjacent to each other from the elements (nodes) that form the end or hole of the immersion treatment object, and this analysis process forms the connection part of the object to be immersed. It can be terminated when the attribute setting of the element (node) is reached. Therefore, it is possible to set different attributes for the elements (nodes) on one side and the other side across the connection part of the object to be immersed, and the object to be immersed having a connection part to which a plurality of members are connected. It is possible to quickly and accurately simulate the air pocket.

  According to the method for simulating the occurrence of air stagnation in an object to be immersed according to the present invention, the attribute of an element (node) can be set to air or paint by comparing the center of gravity of the element and the height of the node. Therefore, the attribute of the element (node) can be easily set using the coordinate data of the node without separately performing complicated calculations.

  According to the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention, the element (or the connection part) that forms the connection part after the setting of the attribute of the element (node) is finished at the connection part of the object to be immersed Since the setting of the attribute of the element (node) is continuously executed according to the determination result of the attribute of the adjacent node adjacent to the object, it is possible to accurately simulate even the object to be immersed having a plurality of connection portions.

  According to the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention, the element (or the connection part) that forms the connection part after the setting of the attribute of the element (node) is finished at the connection part of the object to be immersed If the attribute of the element (node) to be compared thereafter is air when the attribute of the element (node) is continuously executed according to the result of the attribute determination of the adjacent node close to), Since the attribute of the element (node) that is the basis of the comparison is returned from the paint to the air and the analysis is terminated, the accuracy of the analysis result can be improved.

  According to the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention, in the simulation method in which the attributes of the nodes are set one after another, a two-dimensional element is generated as data at the connection part of the object to be immersed. The analysis can be terminated depending on whether the node forms an element of this connection.

  According to the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention, the nodes forming the connection part of the object to be immersed have sub-attributes corresponding to the number of adjacent nodes adjacent to the node. Each sub-attribute can be set in accordance with the analysis processing at the adjacent node adjacent to the node.

  According to the method of simulating the occurrence of air accumulation in the object to be immersed according to the present invention, the object to be immersed can be a vehicle body, and in this case, a vehicle body having a complicated shape can be accurately simulated.

  According to the computer-executable program for executing the simulation method for generating air stagnation in the object to be immersed in the present invention, the computer can execute the simulation method for generating stagnation in the object to be immersed in the present invention. .

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 is a block diagram of a fluid analyzing apparatus that executes a simulation method according to the present invention.

  As shown in FIG. 1, a fluid analysis device (computer) 10 that executes a method for simulating the occurrence of air accumulation in an object to be immersed according to the present invention includes a keyboard 11 for inputting analysis conditions of the object to be immersed, an analysis process, and the like. Display 12 for displaying the results, HDD (hard disk drive) 13 for storing various data of the object to be immersed, and FDD (flexible disk drive) 14 for storing the results of analysis processing in FD (flexible disk) And have.

  The fluid analysis apparatus 10 further includes a control unit 18 including a CPU 15, ROM 16 and RAM 17, a keyboard controller 19 of the keyboard 11, a display controller 20 of the display 12, a disk controller 21 of the HDD 13 and the FDD 14, and a fluid analysis apparatus. A network interface controller 23 for connecting 10 to the network 22 is provided, and these can communicate with each other via a system bus 24.

  The CPU 15 constituting the control unit 18 executes the software stored in the ROM 16 and the HDD 13 or the software supplied from the FDD 14 so as to comprehensively control various components connected to the system bus 24. It has become. That is, the CPU 15 reads out software from the ROM 16, HDD 13, or FDD 14 according to a predetermined processing sequence, and executes the program to perform control for realizing the flowchart shown in FIG. 7.

  CPU15 reads the various data of the to-be-immersed processing object used as analysis object from HDD13, and constructs the two-dimensional numerical calculation model divided | segmented into several elements from this read-out various data. Further, the CPU 15 calculates information (data) necessary for realizing the flowchart shown in FIG. 7 based on the constructed numerical calculation model, that is, calculates the centroid points and the like of a plurality of elements. The state of occurrence of air accumulation in the immersion treatment product is displayed on the display 12.

  The RAM 17 constituting the control unit 18 functions as a main memory or work area for the CPU 15. The keyboard controller 19 controls input signals from input means such as the keyboard 11 and a pointing device (not shown), and the display controller 20 controls display on the display 12. The disk controller 21 controls access to the HDD 13 and the FDD 14 that store or read a boot program, various applications, editing files, user files, network management programs, and the like. The network interface controller 23 transmits and receives data to and from other devices (not shown) on the network 22.

  Next, a method for simulating the occurrence of air accumulation in an object to be immersed, which is executed by the fluid analyzing apparatus 10, will be described in detail. In this embodiment, the finite element method is used as an analysis method, and an analysis is performed using a shape model formed by connecting a flat plate member and a cylindrical member halved as shown in FIG. Is going.

  2 is an explanatory diagram for explaining the object to be immersed and the coating tank, FIG. 3 is a longitudinal sectional view showing a numerical calculation model of the object to be immersed, and FIG. 4 is a partially enlarged triangular mesh around the multi-edge. 5 is a partial enlarged view, FIG. 5 shows data representing the relationship between the triangular mesh and the node in FIG. 4, and FIG. 6 shows the coordinate data of the node in FIG.

  As shown in FIG. 2, the to-be-immersed object 30 is formed in a bag shape by welding and connecting a flat plate member 31 and a half tubular member 32 to each other. The opening side (the lower side in the figure) of the bag-like portion 33 of the treatment object 30 is directed to the paint tank 40, and the paint tank 40 is provided with a liquid paint (paint) 41 as an electrodeposition solution. Contains a fixed amount. Therefore, when the object to be treated 30 is actually immersed in the liquid paint 41 in the posture shown in FIG. 2, an air pocket (air pocket) is formed in the bag-like portion 33 of the object to be treated 30. Will occur.

  The control unit 18 (see FIG. 1) of the fluid analyzing apparatus 10 generates a plurality of two-dimensional elements (triangular meshes) 50, 50,. In order to construct a two-dimensional numerical calculation model, for example, when the analysis target is a vehicle body, it is used for simulation of collision deformation of the vehicle body. Can be used.

  The to-be-immersed object 30 is a plurality of triangular meshes 50, 50 surrounded by a plurality of nodes (nodes) 51, 51... Are formed. As shown by the broken-line circle A, the free edge portion 52 that forms the end or hole portion of the object to be immersed 30 includes a plurality of free edge nodes 53, 53... And free edge meshes 54, 54. -Is arranged. In the figure, the shaded portion represents the free edge mesh 54.

  A multi-edge 55 (thick line in the figure) as a connecting portion is formed between the flat plate member 31 and the cylindrical member 32 forming the treatment object 30 as shown by a broken-line circle B portion. On the multi-edge 55, three triangular meshes 50, 50, 50 sharing a pair of adjacent nodes 51, 51 on the multi-edge 55 are arranged. Thus, what connected the connection of the nodes which share at least 3 triangular mesh is called multi edge in this invention.

  When the periphery of the multi-edge 55 of the workpiece 30 is schematically shown, it is expressed as shown in FIG. Hereinafter, description will be made using alphabets as symbols for nodes, triangular meshes, and the like.

  A plurality of triangular meshes (M) forming a multi-edge (ME), that is, symbols A1 to A11, B1 to B11, and C1 to C11, and nodes (N) forming these triangular mesh groups A, B, and C That is, the symbols a to y are represented by data as shown in FIGS. 5 and 6, respectively. These data are stored in the RAM 17 (see FIG. 1), and each data is assigned to a unique memory address. As shown in the shaded portion in the figure, each triangular mesh A1, B1, C1 forms a multi-edge (ME) as a set.

  Next, the contents of the program executed by the control unit 18 of the fluid analyzing apparatus 10 will be described with reference to FIGS. FIG. 7 is a flowchart (main routine) showing an air pocket generation simulation method according to the present invention, FIG. 8 is a flowchart (subroutine) showing air pocket determination calculation, and FIGS. 9 (a), (b), and (c) are shown. Explanatory drawing explaining the mode of attribute change of a triangular mesh is each represented.

  As shown in FIG. 7, first, when the fluid analyzing apparatus 10 is turned on and electric power is supplied to the control unit 18, initial setting of the control unit 18 is performed, and analysis processing software is transferred from the HDD 13 or the like to the RAM 17. Is read and the program for executing the method for simulating the occurrence of air accumulation in the object to be immersed according to the present invention is executed (step S1).

  Next, the operator inputs the part (P_i) to be analyzed, that is, the workpiece 30 shown in FIG. 2 via the keyboard 11 (step S2).

  In step S3, the original data corresponding to the part (P_i) input in step S2, that is, in the case where the part (P_i) constitutes the vehicle body, the shape data (diverted) used for the vehicle body body collision deformation simulation, etc. Data) is read from the HDD 13. Then, the read shape data of the part (P_i) is divided into a plurality of two-dimensional elements (triangular meshes), and the data (see FIGS. 5 and 6) generated thereby is stored in the RAM 17 to be a numerical calculation model. Build up.

  In step S4, the immersion direction of the object to be immersed 30 in the paint tank 40 (see FIG. 2), that is, the gravity direction (G) of the component (P_i) is input by operating the keyboard 11 of the operator. And the control part 18 updates the coordinate data (refer FIG. 6) of the node (N) in all the triangular meshes (M) which form components (P_i) based on the gravity direction (G) input, and this Coordinate data in consideration of the direction of gravity (G) is stored in the RAM 17.

  In step S5, the attribute of all triangular meshes (M) forming the part (P_i) is set to air (A) based on the data stored in the RAM 17 in step S4, and thereby the data used in the subsequent step S6. This completes the initial condition setting. Here, Step S3 and Step S5 constitute the first step in the present invention.

  In step S6, the air pocket determination calculation shown in the subroutine of FIG. 8 is executed. In step S7, post-processing of the calculation result in step S6 is executed, and in subsequent step S8, the analysis result is displayed to the operator by performing graphic display to the outside via the display 12, and the analysis processing is ended.

  Next, the processing contents of the air pocket determination calculation will be described in detail. In the analysis processing after step S6A shown in FIG. 8, the air pocket determination calculation according to the first embodiment of the present invention is executed.

  In step S10, a free edge mesh (FM_i) that forms an end or a hole is extracted from all the triangular meshes (M) that form the part (P_i), and a plurality of extracted free edge meshes (FM_i) are extracted. Set to initial boundary mesh (initial boundary element). Then, the attribute of the initial boundary mesh is set to paint (liquid) (see the shaded portion in FIG. 3) to obtain a liquid mesh (LM_i). Here, step S10 constitutes a second step in the present invention.

  In step S11, one liquid mesh (LM_i) is selected from the plurality of liquid meshes (LM_i). In the subsequent step S12, the air mesh (AM_i) adjacent to the liquid mesh (LM_i) selected in step S11 is extracted, that is, the adjacent mesh (NM) sharing a pair of nodes (N) forming the liquid mesh (LM_i). Set (adjacent element). Here, step S12 constitutes a third step in the present invention.

  In step S13, it is determined whether the air mesh (AM_i) extracted in step S12 is on the opposite side of the liquid mesh (LM_i) across the multi-edge (ME), and the air mesh (AM_i) is determined to be multi-edge. When it is determined (yes) that it is on the opposite side of the liquid mesh (LM_i) across (ME), that is, there is an air mesh (AM_i) that shares the multi-edge (ME) that forms the liquid mesh (LM_i) The process proceeds to step S14. On the other hand, when it is determined that the air mesh (AM_i) is not on the opposite side of the liquid mesh (LM_i) across the multi-edge (ME), the process proceeds to step S15.

  In step S15, the center of gravity of the liquid mesh (LM_i) as the initial boundary mesh is calculated, and the center of gravity of the air mesh (AM_i) as the adjacent mesh (NM) is calculated. Note that each centroid point is calculated by a predetermined calculation using the coordinate data (see FIG. 6) of the node (N) forming each triangular mesh (M). Then, by comparing the height of each center of gravity (comparison of Z coordinate values), the center of gravity of the liquid mesh (LM_i) is equal to or higher than the center of gravity of the air mesh (AM_i). If it is determined, the process proceeds to step S16.

  However, in step S15, the heights of specific nodes (N) forming the triangular mesh (M) may be compared without comparing the heights of the center of gravity points as described above. That is, when the triangular mesh A1 and the triangular mesh C1 shown in FIG. 4 are compared, the highest node (highest node) a that forms the triangular mesh A1 and the highest node that forms the triangular mesh C1 are present. Compare the height with the highest node g. The heights of the lowest nodes (lowest nodes) at the lowest position may be compared. In the case of the triangular mesh A1, the symbol h is the lowest node, and in the case of the triangular mesh C1, the symbol t is It becomes the lowest node. In this way, by comparing the heights of specific nodes (N) forming each triangular mesh (M) to be compared, the coordinate data (Z coordinate value) shown in FIG. 6 can be used as it is. .

  In step S16, the air mesh (AM_i) is set to the liquid mesh (LM_i), as shown by the determination arrow from the triangular mesh group A direction in FIGS. Change from A) to liquid (L).

  On the other hand, when it is determined as no in step S15, that is, when it is determined that the height of the center of gravity of the liquid mesh (LM_i) is lower than the height of the center of gravity of the air mesh (AM_i), FIGS. As shown by the determination arrows from the triangular mesh group B direction and C direction, the process proceeds to step S14 without changing the attribute of the air mesh (AM_i). Here, Step S15 and Step S16 constitute a fourth step in the present invention.

  In step S14, it is determined whether or not the analysis processing in steps S13, S15, and S16 has been executed for all the air meshes (AM_i) extracted in step S12. When it determines with no by step S14, the analysis process of step S13, S15, S16 is performed about the other air mesh (AM_i) extracted by step S12. If it is determined yes in step S14, that is, if it is determined (yes) that the analysis processing of steps S13, S15, and S16 has been executed for all the air meshes (AM_i) extracted in step S12, the process proceeds to step S17.

  In step S17, first, the liquid mesh (LM_i) whose attributes have been changed in step S16 and finished the analysis processing is set as a secondary boundary mesh (secondary boundary element). Then, it is determined whether analysis processing has been performed for all of the set liquid mesh (LM_i) as the secondary boundary mesh and the liquid mesh (LM_i) as the initial boundary mesh extracted in step S10.

  If NO is determined in step S17, the process returns to step S11, and the liquid mesh (LM_i) as the initial boundary mesh that has not been analyzed and the liquid mesh (LM_i) that has been set as the secondary boundary mesh after the analysis process are completed. ) Continue the analysis process. If it is determined yes in step S17, the process proceeds to step S18.

  As described above, the setting of the secondary boundary mesh performed in step S17 and the analysis process using the secondary boundary mesh performed by returning to step S11 include the fifth step and the sixth step in the present invention. It is composed. In addition, when the analysis process is repeatedly executed in steps S11 to S17 and the adjacent meshes (NM) extracted one after another form a multi-edge (ME), the analysis process converges. The logic for ending the analysis process constitutes the seventh step in the present invention.

  Here, the to-be-immersed object 30 having the shape shown in FIGS. 2 and 3 can perform air pocket determination by the analysis process up to step S17. That is, by the analysis process up to step S17, the attribute of the triangular mesh (M) is set as shown in FIG. 9C, thereby determining the occurrence of an air pocket as shown by the hatched portion in the figure and performing the analysis process. Converge. In the analysis processing after step S18, it is possible to cope with the air pocket determination of the objects to be immersed 60 and 70 having the shape shown in FIGS. 10 and 11, and the analysis result of the object to be immersed 30 is the analysis after step S18. There is no change by executing the process.

  10 (a), (b), and (c) are explanatory diagrams for explaining a state of changing the attribute of the triangular mesh in the object to be immersed having a plurality of multi-edges, and FIGS. 11 (a) and 11 (b) are analysis diagrams. Explanatory drawing explaining the correction example of a process result is each represented.

  The to-be-immersed object 60 shown in FIG. 10 has first and second multi-edges (ME_1) and (ME_2), and each of A to D is directed toward each multi-edge (ME_1) and (ME_2). The attribute is determined from four directions.

  In step S18, the mesh group (MG_i) of the triangular mesh (M) connected to the multi-edge (ME) is extracted, that is, the triangular meshes (LM_a), (LM_b), (AM_c) as shown in FIG. ) Are extracted along the extending direction of the first multi-edge (ME_1).

  In step S19, one mesh group (MG_i) is selected from the plurality of mesh groups (MG_i) extracted in step S18. In the following step S20, only one of the triangular meshes (M) constituting the mesh group (MG_i) selected in step S19, that is, the triangular meshes (LM_a), (LM_b), (AM_c) is the air mesh (AM_i). It is determined whether or not there is. Here, step S20 constitutes an eighth step in the present invention.

  In step S20, for example, when there are two air meshes (AM_i) (see the object to be immersed 30) or three (see the second multi-edge (ME_2)), it is determined as no and the step Proceed to S22. In the first multi-edge (ME_1) in the component (P_j) of FIG. 10, since only the attribute of the triangular mesh (AM_c) forming the first multi-edge (ME_1) is air (A), the process goes to step S21. move on.

  In step S21, the attribute of the air mesh (AM_i) determined to be yes in step S20 is changed to liquid (L) to obtain a liquid mesh (LM_i). That is, as shown in FIGS. 10A and 10B, the attribute of the triangular mesh (AM_c) is changed to the liquid mesh (LM_i). Here, step S21 constitutes a ninth step in the present invention.

  In subsequent step S22, it is determined whether or not the analysis processing of step S20 and step S21 has been executed for all of the plurality of mesh groups (MG_i) extracted in step S18, and the analysis processing is still performed for all mesh groups (MG_i). If (No) is not executed, the process returns to Step S19 to execute analysis processing for another mesh group (MG_i).

  If it is determined yes in step S22, the process proceeds to step S23. In this step S23, it is determined whether or not there is a triangular mesh (M) whose attribute has been changed in step S21 upstream thereof, and the attribute has been changed. Set the triangular mesh (M) as the initial boundary mesh. In the component (P_j) shown in FIG. 10, since the triangular mesh (AM_c) is changed to the liquid mesh (LM_i) in step S21, it is determined yes in step S23, and the liquid mesh (LM_i) is initialized. The boundary mesh is set and the process returns to step S11. Here, step S23 constitutes a tenth step in the present invention.

  After returning to step S11, the analysis process is executed using the liquid mesh (LM_i) set in step S21 as an initial boundary mesh, and then the next multi-edge (ME), that is, the second multi-edge shown in FIG. The analysis process similar to the above is executed until the edge (ME_2) is reached. Thereby, as shown in FIG.10 (c), the analysis process of components (P_j) converges, As a result, it determines with the air pocket as shown to a hatching part in a figure generate | occur | producing in the to-be-immersed process object 60. .

  If it is determined no in step S23, the process proceeds to step S24, where the attributes of the plurality of liquid meshes (LM_i) connected to the node (N) on the multi-edge (ME) are confirmed and correction is required. Then, the modification processing of the attribute is executed. Here, since the immersion treatment objects 30 and 60 described above are shapes in which the attribute setting of the liquid mesh (LM_i) in the multi-edge (ME) is correctly set, the attribute correction process is not executed. In subsequent step S25, the analysis processing of the air pocket determination calculation ends, and the process proceeds to step S7 (see FIG. 7) of the main routine.

  Next, an example of a shape in which the modification process of the attribute of the liquid mesh (LM_i) connected to the node (N) on the multi-edge (ME) is executed in step S24 will be described based on FIG.

  The to-be-immersed object 70 shown in FIG. 11 has one multi-edge (ME) like the above-mentioned to-be-immersed object 30, and attributes from three directions A to C toward the multi-edge (ME). Judgment is made. However, in the object 70 to be immersed, the determination process from the triangular mesh group C direction, that is, the determination process in which the attribute is determined to be air (A) is performed in the direction of gravity (G) rather than the multi-edge (ME). In this respect, it is different from the shape of the object to be immersed 30.

  As shown in FIG. 11, according to the part (P_k) as the object to be immersed 70, by executing the analysis processing in step S <b> 20 and step S <b> 21 in FIG. 8, the original attribute as shown in FIG. The triangular mesh (M) to be determined as air (A) is changed to the liquid mesh (LM_i).

  Thereafter, it is determined as yes in step S23, the process returns to step S11, the analysis process similar to the above is repeated, and the process returns to step S23 again. Thus, the process returns to step S11 and the analysis process (second analysis process) is executed again. However, in the determination in step S23 after the second analysis process is completed, the attribute is determined in the upstream step S21. It is determined that there is no changed mesh and the process proceeds to step S24.

  In step S24, in step S16 in the second analysis process, the attribute of the adjacent mesh (NM) of the liquid mesh (LM_i) shown in FIG. The liquid mesh (LM_i) is assumed to be an air mesh (AM_i), and a correction process for correcting the liquid mesh (LM_i) whose attribute has been changed in the first analysis process to an air mesh (AM_i) is executed. Thereafter, as shown in FIG. 11 (b), the analysis processing of the component (P_k) converges, and as a result, it is determined that air pockets as shown by hatching portions in the drawing are generated in the workpiece 60. (Step S25). In step S24, the correction process is executed for all the liquid meshes (LM_i) to be corrected along the extending direction of the multi-edge (ME).

  As described above in detail, according to the method of generating air pools in the object to be immersed according to the first embodiment, the attribute of the triangular mesh (M) is set to the free edge mesh (FM_i) that forms the object to be immersed. This is set by analyzing adjacent meshes (NM) that are adjacent to each other, and this analysis process has reached the setting of the attributes of the triangular mesh (M) that forms the multi-edge (ME) of the object to be immersed. Can be terminated in case. Therefore, the triangular mesh (M) on one side and the other side sandwiching the multi-edge (ME) can be set to different attributes, respectively, and the air pool in the immersion treatment object having the multi-edge (ME) can be quickly and Accurate simulation is possible.

  In addition, according to the simulation method for the occurrence of air accumulation in the object to be immersed according to the first embodiment, the attribute of the triangular mesh (M) is compared with the height of the center of gravity of the triangular mesh (M). It can be set to (A) or liquid (L). Therefore, it is possible to easily set the attribute of the triangular mesh (M) using the coordinate data of the node (N) forming the triangular mesh (M) without performing another complicated calculation. Triangle mesh (M) attributes can also be set by comparing the heights of specific nodes (N) (highest nodes or lowest nodes) that form each triangular mesh (M) to be compared. In this case, the coordinate data (Z coordinate value) shown in FIG. 6 can be used as it is. Therefore, calculation for height comparison is not required, and the attributes of the triangular mesh (M) can be set more easily.

  Furthermore, according to the method for simulating the occurrence of air accumulation in the object to be immersed according to the first embodiment, after the setting of the attribute of the triangular mesh (M) is terminated at the multi-edge (ME), the multi-edge (ME) Since the setting of the attribute of the triangular mesh (M) is continuously executed according to the determination result of the attribute of the triangular mesh (M) that forms the object to be immersed (FIG. 10) The simulation can be performed accurately also in the object to be immersed 60).

  Moreover, according to the simulation method of the air clogging generation | occurrence | production in the to-be-immersed process object which concerns on 1st Embodiment, after finishing the setting of the attribute of a triangular mesh (M) by multi edge (ME), the said multi edge (ME) When the attribute setting of the triangular mesh (M) is continuously executed according to the determination result of the attribute of the triangular mesh (M) forming the triangle mesh (M), the attribute of the triangular mesh (M) to be compared thereafter is air ( In the case of A), the attribute of the triangular mesh (M) that is the basis of the comparison is returned from the liquid (L) to the air (A) and the analysis is terminated, so the accuracy of the analysis result is improved (Fig. 11 immersion) Processed product 70).

  Furthermore, according to the method for simulating the occurrence of air accumulation in the object to be immersed according to the first embodiment, the object to be immersed can be a vehicle body, and in this case, the vehicle body having a complicated shape is accurately simulated. be able to.

  Next, an air pool generation simulation method for the object to be immersed according to the second embodiment of the present invention will be described in detail with reference to FIGS. 12 and 13. FIG. 12 is a flowchart (subroutine) showing air pocket calculation in the second embodiment, and FIGS. 13 (a), (b), and (c) are explanatory diagrams for explaining the state of node attribute change. .

  In the first embodiment, the analysis process is executed using the triangular mesh (M) that forms the object to be immersed. In the second embodiment, the shape data of the object to be immersed is used. The analysis process is executed using the node (N) arranged on the surface. Detailed description of the same parts as those of the first embodiment will be omitted.

  In the analysis processing after step S6B shown in FIG. 12, the air pocket determination calculation according to the second embodiment of the present invention is executed. In step S3 (see FIG. 7) upstream of step S6B, only the coordinate data shown in FIG. 6 is generated based on the shape data of the part (P_i), and this coordinate data is stored in the RAM 17 to construct a numerical calculation model. It is like that.

  In step S5 (see FIG. 7), the attributes of all the nodes (N) forming the part (P_i) (the object to be immersed 30) are set to air (A), so that the initial condition setting is completed. It has become. Here, step S3 and step S5 shown in FIG. 7 constitute a first step in the present invention.

  In step S30, out of all the nodes (N) forming the part (P_i), the free edge node (FN_i) forming the end or the hole is extracted, and the plurality of extracted free edge nodes (FN_i) are initialized. Set to node (initial node). Then, the attribute of the initial node is set to the liquid (L) to be the liquid node (LN_i). Here, step S30 constitutes a second step in the present invention.

  In step S31, one liquid node (LN_i) is selected from the plurality of liquid nodes (LN_i). In subsequent step S32, it is determined whether or not the liquid node (LN_i) selected in step S31 is a node (N) on the multi-edge (ME). If it is determined yes in step S32, the analysis process based on the liquid node (LN_i) is terminated, the process returns to step S31, and another liquid node (LN_i) is selected. If it is determined no in step S32, the process proceeds to step S33.

  In step S33, an air node (AN_i) as an adjacent node (adjacent node) that is adjacent to the liquid node (LN_i) selected in step S31 is extracted. This air node (AN_i) can be extracted by using the coordinate data shown in FIG. Here, step S33 constitutes a third step in the present invention.

  In step S34, it is determined whether or not the air node (AN_i) extracted in step S33 is a node (N) on the multi-edge (ME). If it is determined yes, the process proceeds to step S35, and no and When it determines, it progresses to step S36.

  In step S36, the heights of the liquid node (LN_i) as the initial node and the air node (AN_i) as the adjacent node are compared using the coordinate data shown in FIG. If it is determined as yes in step S36, that is, if it is determined that the height of the liquid node (LN_i) is equal to or higher than the height of the air node (AN_i), the process proceeds to step S37.

  In step S37, the air node (AN_i) is set to the liquid node (LN_i), that is, its attribute is set to air (A) as shown by the determination arrow from the direction of the node group A in FIGS. ) To liquid (L).

  On the other hand, if the determination in step S36 is no, that is, if it is determined that the height of the liquid node (LN_i) is lower than the height of the air node (AN_i), the node group B in FIGS. 13 (a) and 13 (b). As shown by the determination arrow from the direction and the C direction, the process proceeds to step S35 without changing the attribute of the air node (AN_i). Here, step S36 and step S37 constitute the fourth step in the present invention.

  In step S35, it is determined whether or not the analysis processing in steps S34, S36, and S37 has been executed for all the air nodes (AN_i) extracted in step S33. If it is determined no in step S35, the analysis processing in steps S34, S36, and S37 is executed for the other air node (AN_i) extracted in step S33. If it is determined yes in step S35, that is, if it is determined (yes) that the analysis processing of steps S34, S36, and S37 has been executed for all the air nodes (AN_i) extracted in step S33, the process proceeds to step S38.

  In step S38, first, the liquid node (LN_i) whose attribute has been changed in step S37 and finished the analysis processing is set as a secondary node (secondary node). Then, it is determined whether or not the analysis processing has been performed for all of the set liquid node (LN_i) as the secondary node and the liquid node (LN_i) as the initial node extracted in step S30.

  If it is determined no in step S38, the process returns to step S31, and the liquid node (LN_i) as the initial node that has not finished the analysis process and the liquid node (LN_i) set as the secondary node after the analysis process have been finished. Continue the analysis process. If it is determined as yes in step S38, the process proceeds to step S39.

  As described above, the setting of the secondary node performed in step S38 and the analysis process using the secondary node executed after returning to step S31 constitute the fifth step and the sixth step in the present invention. ing. In addition, when the analysis process is repeatedly executed in steps S31 to S38 and the adjacent nodes extracted one after another are on the multi-edge (ME), the analysis process converges (see FIG. 13C). The logic for ending this analysis process constitutes the seventh step in the present invention.

  In step S39, as shown in FIG. 13B, a pair of adjacent nodes (N_i) and (N_j) on the multi-edge (ME) are extracted. In subsequent step S40, the closest node (N_k) (adjacent node) is selected from the pair of nodes (N_i) and (N_j) extracted in step S39. Here, there are three nodes (N_k) in the component (P_i) around the pair of nodes (N_i) and (N_j) as shown in FIG.

  In step S41, whether or not there is only one air node (AN_i) among a plurality of nodes (N_k) closest to each of the pair of nodes (N_i) and (N_j), or all nodes (N_k) ) Is a liquid node (LN_i). If it is determined yes in step S41, the process proceeds to step S42, and if it is determined no, the process proceeds to step S43. Here, step S39 thru | or step S41 comprise the 8th step in this invention.

  The determination in step S41 for the component (P_i) illustrated in FIG. 13 is determined to be no because the two nodes (N_k) are air nodes (AN_i). In addition, the to-be-immersed process object 60 shown in FIG. 10 is determined to be yes in step S41.

  In step S42, the attributes of the pair of nodes (N_i) and (N_j) on the air node (AN_i) and multi-edge (ME) used in the determination in step S41 are changed to liquid nodes (LN_i). The process executed in step S42 is a process for handling the shape of the workpiece 60 shown in FIG. 10, that is, the workpiece to be immersed having a plurality of multi-edges (ME). Here, step S42 constitutes a ninth step in the present invention.

  In subsequent step S43, it is determined whether or not the analysis processing in steps S39 to S42 has been executed for all the nodes (N) on the multi-edge (ME), and if it is determined no in step S43, the process proceeds to step S39. Returning to step S44 if it is determined yes.

  In step S44, it is determined whether or not there is a node (N_k) as a neighboring node whose attribute has been changed in step S42 upstream thereof, and the node (N_k) whose attribute has been changed to be a liquid node (LN_i) is determined. Set to the initial node. In the component (P_i) shown in FIG. 13, since the node (N_k) changed in step S42 does not exist, it is determined as no in step S44, and the process proceeds to step S45. In addition, the to-be-immersed process object 60 shown in FIG. 10 will determine with yes in step S44, and will return to step S31. Here, step S44 constitutes the tenth step in the present invention.

  In step S45, the process for responding to the shape of the object to be immersed 70 shown in FIG. 11 is executed. That is, the attributes of the pair of nodes (N_i) and (N_j) on the air node (AN_i) and multi-edge (ME) set to the liquid node (LN_i) in step S42 are changed from the liquid (L) to the air (A). The correction processing to return to is performed, so that the accuracy of the analysis result in the workpiece 70 shown in FIG. 11 can be improved.

  Thereafter, in the subsequent step S46, the analysis processing of the air pocket determination calculation ends, and the process proceeds to step S7 (see FIG. 7) of the main routine.

  Also in the second embodiment configured as described above, the same operations and effects as those in the first embodiment described above can be achieved. In addition, according to the second embodiment, since the shape data of the object to be immersed used for the analysis process is only node data (see FIG. 6), the load on the fluid analysis device 10 can be reduced. it can.

  Next, an air pool generation simulation method for the object to be immersed according to the third embodiment of the present invention will be described in detail with reference to FIGS. 14 and 15. FIG. 14 is a flowchart (subroutine) showing air pocket calculation in the third embodiment, and FIG. 15 is an explanatory diagram for explaining a state of changing attributes of triangular mesh nodes around the multi-edge.

  The third embodiment differs from the second embodiment described above in that the analysis process is performed using a triangular mesh (M) that contacts the multi-edge (ME). Detailed description of the same parts as in FIG.

  In the analysis processing after step S6C shown in FIG. 14, the air pocket determination calculation according to the third embodiment of the present invention is executed. In step S3 (see FIG. 7) upstream of step S6C, based on the shape data of the part (P_i), in addition to the generation of coordinate data shown in FIG. 6, the triangular mesh (M) that forms the multi-edge (ME), that is, 15, codes a1 to a6, b1 to b6, and c1 to c6 are generated, and these data are stored in the RAM 17 to construct a numerical calculation model.

  In step S5 (see FIG. 7), the attributes of all the nodes (N) forming the part (P_i) (the object to be immersed 30) and all the triangular meshes (M) forming the multi-edge (ME) are set to air ( Set to A), and the initial condition setting is completed. Here, step S3 and step S5 shown in FIG. 7 constitute a first step in the present invention.

  In the third embodiment, as shown in FIG. 14, the processes shown in step S50 and step S51 are executed between step S32 and step S33, as compared to the second embodiment. Yes.

  In step S50, whether or not the liquid node (LN_i) whose attributes have been changed one after another (including the free edge node (FN_i) as the initial node) forms the triangular mesh (M) that forms the multi-edge (ME) is determined. If yes, the process proceeds to step S51. If no, the process proceeds to step S33.

  In step S51, the attribute of the triangular mesh (M) forming the multi-edge (ME) is changed to liquid (L), that is, the air mesh (AM_i) is changed to liquid mesh (LM_i), and then the process goes to step S31. Returned.

  By repeatedly executing the analysis process in steps S31 to S38 including steps S50 and S51, as shown in FIG. 15, the attribute change from the node group A direction to the liquid node (LN_i) of the air node (AN_i) is performed. Accordingly, the triangular meshes a1 to a6 forming the multi-edge (ME) are set as the liquid mesh (LM_i).

  In this way, when the liquid node (LN_i) to be analyzed one after another forms a triangular mesh (M) that forms a multi-edge (ME), the analysis process converges, and this analysis process The logic to end the process constitutes the seventh step in the present invention.

  In step S52, as shown in FIG. 15, a triangular mesh (M) sharing a pair of adjacent nodes (N_i) and (N_j) on the multi-edge (ME) is extracted. That is, a group of triangular meshes (M) composed of triangular mesh (M) groups (a1, b1, c1), (a2, b2, c2)... Shown in FIG.

  In step S53, it is determined whether or not there is an air mesh (AM_i) in the triangular mesh (M) group. If it is determined yes, the process proceeds to step S54. If it is determined no, the process proceeds to step S56. move on. In the part (P_i), since two air meshes (AM_i) exist as shown in FIG. 15, it is determined as yes.

  In step S54, it is determined whether or not there is only one air mesh (AM_i) in the triangular mesh (M) group. If it is determined yes, the process proceeds to step S55, and if it is determined no, Proceed to step S57. In the part (P_i), since there are two air meshes (AM_i) as shown in FIG. 15, it is determined as no.

  In step S55, the attribute of the air mesh (AM_i) found in step S53 is changed to the liquid mesh (LM_i). In subsequent step S56, the multi-edge (ME) forming the liquid mesh (LM_i) whose attribute is changed in step S55. The attribute of the pair of upper nodes (N_i) and (N_j) is changed to the liquid node (LN_i).

  In step S57, it is determined whether or not the analysis processing in steps S53 to S56 has been executed for all of the triangular meshes (M) forming the multi-edge (ME). If it is determined no, the process returns to step S53, and another triangular mesh (M) group is extracted, and the analysis processing in steps S53 to S56 is executed for the triangular mesh (M) group. When it determines with yes, it progresses to step S58. As described above, the analysis processing in steps S53 to S56 is executed, so that the shape of the object to be immersed 60 shown in FIG. 10 can be handled.

  In step S58, it is determined whether there is a triangular mesh (M) whose attribute has been changed in upstream step S55 among the triangular meshes (M) forming the multi-edge (ME). The part (P_i) shown in FIG. 15 is determined to be no and the process proceeds to step S59, and the immersion object 60 shown in FIG. 10 is determined to be yes and the process returns to step S31.

  In step S59, a process for responding to the shape of the workpiece 70 shown in FIG. 11 is executed. That is, the attributes of the triangular mesh (M) set for the liquid mesh (LM_i) in step S55 and the attributes of the pair of nodes (N_i) and (N_j) set for the liquid node (LN_i) in step S56 are A correction process for returning from (L) to air (A) is executed, so that the accuracy of the analysis result in the object 70 to be immersed shown in FIG. 11 can be improved.

  Also in the third embodiment configured as described above, the same operations and effects as in the first embodiment described above can be achieved. In addition, according to the third embodiment, a triangular mesh (M) is generated as data in the multi-edge (ME) of the object to be immersed, and the nodes (N) to be analyzed one after another are Since the analysis can be ended depending on whether or not the triangular mesh (M) of the edge (ME) is formed, the load on the fluid analysis device 10 can be reduced.

  Next, an air pool generation simulation method for an object to be immersed according to the fourth embodiment of the present invention will be described in detail with reference to FIGS. 16 and 17. FIG. 16 is a flowchart (subroutine) showing air pocket calculation in the fourth embodiment, and FIG. 17 is an explanatory diagram for explaining the state of attribute change of triangular mesh nodes around the multi-edge.

  Compared to the second embodiment described above, the fourth embodiment has sub-attributes for all the nodes (N) forming the treatment object 30 (see the broken line circle in FIG. 17). The difference is that analysis processing is executed using. Detailed description of the same parts as those of the second embodiment will be omitted.

  In the analysis processing after step S6D shown in FIG. 16, the air pocket determination calculation according to the fourth embodiment of the present invention is executed. In step S3 (see FIG. 7) upstream of step S6D, based on the shape data of the part (P_i), in addition to the generation of the coordinate data shown in FIG. 6, all nodes (N) forming the part (P_i) It has attribute information. These data are stored in the RAM 17 to construct a numerical calculation model. However, the sub-attribute information may be provided only to the node (N) on the multi-edge (ME). In this case, the load on the fluid analysis device 10 can be reduced.

  The sub attribute of the node (N) on the multi-edge (ME) is generated corresponding to the number of adjacent nodes that are adjacent to the node (N). That is, in the component (P_i) shown in FIG. 17, the node (N) on the multi-edge (ME) has three sub-attributes. In FIG. 17, the display of sub-attributes of nodes (N) other than the node (N) on the multi-edge (ME) is omitted.

  In step S5 (see FIG. 7), the sub-attributes of all the nodes (N) forming the part (P_i) are set to air (A), thereby completing the initial condition setting. Here, step S3 and step S5 shown in FIG. 7 constitute a first step in the present invention.

  In the fourth embodiment, as shown in FIG. 16, the processing shown in steps S60 to S63 is executed between step S33 and step S35, as compared to the second embodiment. Yes.

  In step S60, the height of the liquid node (LN_i) selected in step S31 and the height of the air node (AN_i) extracted in step S33 are compared. When the height of the liquid node (LN_i) is equal to or higher than the height of the air node (AN_i) (yes), the process proceeds to step S61, and the height of the liquid node (LN_i) is set to the air node (AN_i). If the height is lower than (), the process proceeds to step S35.

  In step S61, it is determined whether or not the air node (AN_i) to be compared in step S60 is on the multi-edge (ME). If the determination is yes, the process proceeds to step S62, and the determination is no Then, the process proceeds to step S63.

  In step S62, the sub attribute on the determination direction side of the air node (AN_i), that is, the sub attribute on the determination direction side of the node group A is changed to liquid (L) as shown in FIG. Thereby, in the component (P_i) in FIG. 17, the sub-attributes are respectively set as shown by the broken-line circle in the drawing. In step S63, all the sub attributes of the air node (AN_i) are changed to liquid (L). Here, step S62 constitutes a sixth step in the present invention.

  By repeatedly executing the analysis process in steps S31 to S38 including steps S60 to S63, the sub-attribute of each node (N) is set and the analysis process converges as shown in FIG. The logic for ending this analysis process constitutes the seventh step in the present invention.

  In step S64, the node (N) on the multi-edge (ME) is extracted. In step S65, whether or not only one sub attribute of the node (N) extracted in step S64 is air (A), or whether or not all of the sub attributes of the node (N) are liquid (L). Determine whether. If it is determined yes in step S65, the process proceeds to step S66. If it is determined no, the process proceeds to step S67. In the part (P_i), as shown in FIG. 17, since there are two sub-attributes whose attributes are air (A), it is determined as no.

  In step S66, all of the sub attributes in the node (N) on the multi-edge (ME) are set to liquid (L). That is, the node (N) on the multi-edge (ME) is changed to the liquid node (LN_i).

  In step S67, it is determined whether or not the analysis processing in steps S65 and S66 has been executed for all nodes (N) on the multi-edge (ME). When it determines with no, it returns to step S64, extracts the node (N) on other multi edge (ME), and performs the analysis process in step S65, S66 about the said node (N). When it determines with yes, it progresses to step S68. As described above, the analysis processing in steps S65 and S66 is performed, so that the shape of the object to be immersed 60 shown in FIG. 10 can be handled.

  In step S68, it is determined whether or not the sub attribute of the node (N) on the multi-edge (ME) has been changed in the upstream step S66. The part (P_i) shown in FIG. 15 is determined to be no, and the process proceeds to step S69. The immersion object 60 illustrated in FIG. 10 is determined to be yes, and the process returns to step S31.

  In step S69, the process for responding to the shape of the object to be immersed 70 shown in FIG. 11 is executed. That is, the correction process for returning the sub-attribute of the node (N) set to the liquid mesh (LM_i) in step S66 to the state before the attribute change is executed, and the analysis result of the immersion treatment object 70 shown in FIG. The accuracy is improved.

  Also in the fourth embodiment configured as described above, the same operations and effects as those in the first embodiment described above can be achieved. In addition, according to the fourth embodiment, the shape data of the object to be immersed used for the analysis process is only the node data (see FIG. 6) having the sub attribute. The load can be made relatively small. In addition, since the sub-attribute of the node (N) that forms the multi-edge (ME) can be set according to the analysis processing of the adjacent node adjacent to the node (N), the accuracy of the analysis result Can be further improved.

  In addition, this invention is not limited to each embodiment mentioned above, A various change is possible in the range which does not deviate from the summary. For example, in each of the above-described embodiments, it has been described that the object to be immersed can be applied to the vehicle body. However, the present invention is not limited to this. For example, the vehicle body frame of a railway vehicle, the cabin of a construction machine, and the like are covered. It can also be a target of the immersion treatment.

It is a block diagram of the fluid analysis apparatus which performs the simulation method concerning the present invention. It is explanatory drawing explaining a to-be-immersed processed material and a coating tank. It is a longitudinal cross-sectional view which shows the numerical calculation model of a to-be-immersed process thing. It is the elements on larger scale which expand and show the triangular mesh of a multi-edge periphery partially. It is the data showing the relationship between the triangular mesh of FIG. 4, and a node. It is the coordinate data of the node of FIG. It is a flowchart (main routine) which shows the air pocket generation | occurrence | production simulation method which concerns on this invention. It is a flowchart (subroutine) which shows air pocket determination calculation. (A), (b), (c) is explanatory drawing explaining the mode of an attribute change of a triangular mesh. (A), (b), (c) is explanatory drawing explaining the mode of the attribute change of the triangular mesh in the to-be-immersed process thing which has a some multi edge. (A), (b) is explanatory drawing explaining the example of correction of an analysis process result. It is a flowchart (subroutine) which shows the air pocket calculation in 2nd Embodiment. (A), (b), (c) is explanatory drawing explaining the mode of an attribute change of a node. It is a flowchart (subroutine) which shows the air pocket calculation in 3rd Embodiment. It is explanatory drawing explaining the mode of the attribute change of the triangular mesh node around a multi edge. It is a flowchart (subroutine) which shows the air pocket calculation in 4th Embodiment. It is explanatory drawing explaining the mode of the attribute change of the triangular mesh node around a multi edge.

Explanation of symbols

10 Fluid analyzer (computer)
18 Control Unit 30 Dipped Object 40 Paint Tank 41 Liquid Paint (Paint)
50 Triangular mesh (two-dimensional element)
51 nodes (nodes)
55 Multi-edge (connection part)
60 Product to be immersed 70 Product to be immersed

Claims (24)

It is an air pool generation simulation method in an object to be immersed for simulating an air pool generated in an object to be immersed when immersed in a paint tank,
A first step of dividing the shape data of the object to be immersed having a connection part to which a plurality of members are connected, into a plurality of two-dimensional elements, and setting an attribute of each element to air;
A second step of setting an element that forms an end or a hole of the object to be immersed among the elements to be an initial boundary element, and setting an attribute of the initial boundary element to paint;
A third step of setting an element sharing a node with the initial boundary element as an adjacent element;
A fourth step of analyzing the adjacent element set in the third step using the initial boundary element, and setting an attribute of the adjacent element based on the analysis result;
A fifth step of setting the adjacent element analyzed in the fourth step as a secondary boundary element, and setting an element sharing a node with the secondary boundary element as an adjacent element;
A sixth step of analyzing the adjacent element set in the fifth step using the secondary boundary element and setting an attribute of the adjacent element based on the analysis result;
If it is determined whether an adjacent element adjacent to the secondary boundary element is an element of the connection part, and if it is determined that an adjacent element adjacent to the secondary boundary element is not an element of the connection part, The process of each step is repeated in the order of the fifth step and the sixth step until it is determined that the adjacent element adjacent to the secondary boundary element is the element of the connection portion, and the secondary boundary element is And a seventh step of ending the analysis when it is determined that the element is an element of the connection portion.   2. The method for simulating the occurrence of air accumulation in an object to be immersed according to claim 1, wherein in the fourth step and the sixth step, the initial boundary element, the secondary boundary element, and the adjacent element are used as respective elements. If the height of the centroid of the initial boundary element or the secondary boundary element whose attribute is the paint is higher than the centroid of the adjacent element, the adjacent elements are compared with each other. If the height of the center of gravity of the initial boundary element or the secondary boundary element whose attribute is the paint is lower than the height of the center of gravity of the adjacent element, the attribute of the adjacent element is determined to be paint. A method for simulating the occurrence of air accumulation in an object to be immersed, wherein the attribute is determined to be air.   2. The method for simulating the occurrence of air accumulation in an object to be immersed according to claim 1, wherein in the fourth step and the sixth step, the initial boundary element, the secondary boundary element, and the adjacent element are used as respective elements. The heights of either one of the highest nodes or the lowest nodes are compared, and the height of the node of the initial boundary element or the secondary boundary element whose attribute is paint is the height of the node of the adjacent element. If it is higher than the above, it is determined that the attribute of the adjacent element is paint, and the height of the node of the initial boundary element or the secondary boundary element whose attribute is the paint is lower than the height of the node of the adjacent element In this case, it is determined that the attribute of the adjacent element is air.   In the simulation method of the occurrence of air accumulation in the object to be immersed according to any one of claims 1 to 3, in addition to the seventh step, an attribute of one element among elements sharing the node of the connection portion is An eighth step of determining whether or not it is air, and a ninth step of setting the attribute of the element to paint when it is determined that the attribute of one element is air in the eighth step; A tenth step of setting an element having an attribute set to paint in the ninth step as an initial boundary element, and changing to the third step based on the initial boundary element set in the tenth step. A simulation method for generating air stagnation in an object to be immersed, wherein the analysis process is performed after returning.   The method of simulating the occurrence of air accumulation in an object to be immersed according to claim 4, wherein the attribute of an adjacent element adjacent to the initial boundary element is air in the fourth step executed after returning to the third step. An air pool generation simulation method for an object to be immersed, characterized in that when it is determined that there is an attribute, the attribute of the initial boundary element is returned to air and the analysis is terminated. It is an air pool generation simulation method in an object to be immersed for simulating an air pool generated in an object to be immersed when immersed in a paint tank,
A first step of disposing a plurality of nodes on the surface of the shape data of the object to be immersed having a connection part to which a plurality of members are connected, and setting an attribute of each node to air;
A second step of setting a node forming an end or a hole of the object to be immersed among the nodes as an initial node, and setting an attribute of the initial node as a paint;
A third step of setting a node adjacent to the initial node as an adjacent node;
Analyzing the adjacent node set in the third step using the initial node, and setting the attribute of the adjacent node based on the analysis result;
A fifth step of setting the adjacent node analyzed in the fourth step as a secondary node, and setting a node adjacent to the secondary node as an adjacent node;
A sixth step of analyzing the adjacent node set in the fifth step using the secondary node and setting an attribute of the adjacent node based on the analysis result;
If it is determined whether an adjacent node adjacent to the secondary node is a node of the connection part, and if it is determined that an adjacent node adjacent to the secondary node is not a node of the connection part Until the adjacent node that is adjacent to the secondary node is determined to be a node of the connection portion, the processing of each step is repeated in the order of the fifth step and the sixth step, And a seventh step of ending the analysis when it is determined that the node is a node of the connection part.   The method of simulating the occurrence of air stagnation in the object to be immersed according to claim 6, wherein in the fourth step and the sixth step, the initial node, the secondary node, and the adjacent node are set to respective heights. In comparison, if the height of the initial node or the secondary node whose attribute is paint is higher than the height of the adjacent node, it is determined that the attribute of the adjacent node is paint, and the attribute is paint. In addition, when the height of the initial node or the secondary node is lower than the height of the adjacent node, it is determined that the attribute of the adjacent node is air. .   The method for simulating the occurrence of air stagnation in an object to be immersed according to claim 6 or 7, wherein in addition to the seventh step, a pair of adjacent nodes is extracted at the connecting portion, and the closest node from each of the nodes is extracted. And an eighth step of determining whether an attribute of one of the neighboring nodes is air or whether an attribute of all the neighboring nodes is paint, and the eighth step If it is determined that the attribute of one adjacent node is air or all the attributes of adjacent nodes are paints, the attribute is the paint of the adjacent nodes of air and the attributes of a pair of nodes at the connecting portion. And a tenth step of setting the adjacent node whose attribute is set to paint in the ninth step as an initial node. Air pocket generation simulation method in the dipping treatment product, characterized in that the analysis process returns to the third step based on the initial node set in the tenth step.   9. The method of simulating the occurrence of air accumulation in an object to be immersed according to claim 8, wherein in the fourth step executed after returning to the third step, the attribute of the adjacent node adjacent to the initial node is An air pool generation simulation method for an object to be immersed, characterized in that when it is determined that the air is returned, the attributes of the initial node and the pair of nodes are returned to air and the analysis is terminated.   10. The method for simulating the accumulation of air in the object to be immersed according to claim 6, wherein, in the first step, a two-dimensional element formed by a pair of adjacent nodes in the connection portion is used. The attribute of the element is generated and set to air, and in the seventh step, it is determined whether or not the secondary node forms the element of the connection section generated in the first step. A method for simulating the occurrence of air accumulation in the object to be immersed.   The method for simulating the occurrence of air accumulation in the object to be immersed according to any one of claims 6 to 9, wherein, in the first step, an adjacent node that is adjacent to the node at the node forming the connection portion. A sub-attribute corresponding to the number of the sub-attributes, and in the sixth step, each sub-attribute is set in accordance with the attribute of the secondary node side to be compared. Occurrence simulation method.   12. The method for simulating the occurrence of air accumulation in an object to be immersed according to any one of claims 1 to 11, wherein the object to be immersed is a vehicle body. Method. A computer-executable program for executing an air pool generation simulation method in an object to be immersed for simulating an air pool generated in an object to be immersed at the time of immersion in a paint tank,
A first step of dividing the shape data of the object to be immersed having a connection part to which a plurality of members are connected, into a plurality of two-dimensional elements, and setting an attribute of each element to air;
A second step of setting an element that forms an end or a hole of the object to be immersed among the elements to be an initial boundary element, and setting an attribute of the initial boundary element to paint;
A third step of setting an element sharing a node with the initial boundary element as an adjacent element;
A fourth step of analyzing the adjacent element set in the third step using the initial boundary element, and setting an attribute of the adjacent element based on the analysis result;
A fifth step of setting the adjacent element analyzed in the fourth step as a secondary boundary element, and setting an element sharing a node with the secondary boundary element as an adjacent element;
A sixth step of analyzing the adjacent element set in the fifth step using the secondary boundary element and setting an attribute of the adjacent element based on the analysis result;
If it is determined whether an adjacent element adjacent to the secondary boundary element is an element of the connection part, and if it is determined that an adjacent element adjacent to the secondary boundary element is not an element of the connection part, The process of each step is repeated in the order of the fifth step and the sixth step until it is determined that the adjacent element adjacent to the secondary boundary element is the element of the connection portion, and the secondary boundary element is A computer-executable program for executing a simulation method for generating air stagnation in an object to be submerged, comprising: a seventh step of ending the analysis when it is determined that the element is an element of the connection unit.   The computer-executable program for executing the method of simulating the occurrence of air stagnation in a workpiece to be immersed according to claim 13, wherein in the fourth step and the sixth step, the initial boundary element and the secondary boundary element And the adjacent element are compared with the height of the center of gravity of each element, and the height of the center of gravity of the initial boundary element or the secondary boundary element whose attribute is paint is the height of the center of gravity of the adjacent element. When the height is higher than the height, it is determined that the attribute of the adjacent element is paint, and the height of the centroid of the initial boundary element or the secondary boundary element whose attribute is paint is the height of the centroid of the adjacent element. If it is lower than the above, it is determined that the attribute of the adjacent element is air. Yuta is an executable program.   The computer-executable program for executing the method of simulating the occurrence of air stagnation in a workpiece to be immersed according to claim 13, wherein in the fourth step and the sixth step, the initial boundary element and the secondary boundary element And the adjacent element are compared with the height of either one of the highest nodes or the lowest nodes of the respective elements, and the height of the node of the initial boundary element or the secondary boundary element whose attribute is paint Is higher than the height of the node of the adjacent element, it is determined that the attribute of the adjacent element is paint, and the height of the node of the initial boundary element or the secondary boundary element in which the attribute is paint is the height of the node When the height of the node of the adjacent element is lower than that, the attribute of the adjacent element is determined to be air. Computer executable program to run the simulation method.   In the computer-executable program for executing the simulation method for generating air stagnation in the object to be immersed according to any one of claims 13 to 15, in addition to the seventh step, the node of the connection portion is shared. An eighth step of determining whether or not the attribute of one element among the elements is air; and if the attribute of one element is determined to be air in the eighth step, the attribute of the element is painted And a tenth step of setting an element whose attribute is set to paint in the ninth step as an initial boundary element, and an initial boundary set in the tenth step Returning to the third step based on the element, the analysis process is performed, and the method for simulating the occurrence of air accumulation in the object to be immersed is executed. Computer executable program.   The computer-executable program for executing the method for simulating the occurrence of air stagnation in the object to be immersed according to claim 16, wherein the initial boundary element is set in the fourth step executed after returning to the third step. When it is determined that the attribute of the adjacent adjacent element is air, the attribute of the initial boundary element is returned to air, and the analysis is terminated. A computer executable program. A computer-executable program for executing an air pool generation simulation method in an object to be immersed for simulating an air pool generated in an object to be immersed at the time of immersion in a paint tank,
A first step of disposing a plurality of nodes on the surface of the shape data of the object to be immersed having a connection part to which a plurality of members are connected, and setting an attribute of each node to air;
A second step of setting a node forming an end or a hole of the object to be immersed among the nodes as an initial node, and setting an attribute of the initial node as a paint;
A third step of setting a node adjacent to the initial node as an adjacent node;
Analyzing the adjacent node set in the third step using the initial node, and setting the attribute of the adjacent node based on the analysis result;
A fifth step of setting the adjacent node analyzed in the fourth step as a secondary node, and setting a node adjacent to the secondary node as an adjacent node;
A sixth step of analyzing the adjacent node set in the fifth step using the secondary node and setting an attribute of the adjacent node based on the analysis result;
If it is determined whether an adjacent node adjacent to the secondary node is a node of the connection part, and if it is determined that an adjacent node adjacent to the secondary node is not a node of the connection part Until the adjacent node that is adjacent to the secondary node is determined to be a node of the connection portion, the processing of each step is repeated in the order of the fifth step and the sixth step, And a seventh step of ending the analysis when it is determined that the node is a node of the connection part.   The computer-executable program for executing the method for simulating the occurrence of air stagnation in an object to be immersed according to claim 18, wherein in the fourth step and the sixth step, the initial node, the secondary node, and the When the height of the initial node or the secondary node whose attribute is a paint is higher than the height of the adjacent node by comparing the heights of the adjacent nodes, the attribute of the adjacent node is a paint And determining that the attribute of the adjacent node is air when the height of the initial node or the secondary node whose attribute is paint is lower than the height of the adjacent node. A computer-executable program for executing a method for simulating the occurrence of air accumulation in a soaked object.   In the computer-executable program for executing the method of simulating the accumulation of air in the object to be immersed according to claim 18 or 19, in addition to the seventh step, a pair of adjacent nodes are extracted in the connection portion, The nearest neighbor node is selected from each node, and it is determined whether or not the attribute of one of the neighboring nodes is air or whether the attribute of all the neighboring nodes is paint. And in the eighth step, when it is determined that the attribute of one adjacent node is air, or the attribute of all the adjacent nodes is paint, the adjacent node of which the attribute is air and the connection A ninth step of setting the attribute of the pair of nodes in the part to the paint, and the adjacent node in which the attribute is set to the paint in the ninth step And the 10th step of setting the initial node as the initial node, and the analysis process is performed by returning to the third step based on the initial node set in the tenth step. A computer-executable program for executing the pool generation simulation method.   The computer-executable program for executing the method for simulating the occurrence of air accumulation in an object to be immersed according to claim 20, wherein in the fourth step executed after returning to the third step, adjacent to the initial node. When it is determined that the attribute of the adjacent node in relation is air, the attribute of the initial node and the pair of nodes is returned to the air, and the analysis is ended, and the air pool in the object to be immersed is characterized in that A computer-executable program that executes the generation simulation method.   The computer-executable program for executing the simulation method for generating air stagnation in the object to be immersed according to any one of claims 18 to 21, wherein in the first step, a pair of adjacent nodes in the connection portion The two-dimensional element formed by the above is generated and the attribute of the element is set to air. In the seventh step, the secondary node forms the element of the connection section generated in the first step. A computer-executable program for executing a simulation method for generating air stagnation in an object to be immersed, characterized by determining whether or not the object is to be immersed.   In the computer-executable program for executing the method of simulating the occurrence of air stagnation in the object to be immersed according to any one of claims 18 to 21, in the first step, a node forming the connection portion is provided. Sub-attributes corresponding to the number of adjacent nodes that are adjacent to the node are provided, and in the sixth step, the sub-attributes are set in accordance with the attributes on the secondary node side to be compared. A computer-executable program for executing the method for simulating the occurrence of air accumulation in the object to be immersed.   The computer-executable program for executing the simulation method for generating air stagnation in an object to be immersed according to any one of claims 13 to 23, wherein the object to be immersed is a vehicle body. A computer-executable program for executing a method for simulating the occurrence of air accumulation in an object to be immersed.

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