JP4729294B2 - Fluid analysis method around body panel and fluid analysis program around body panel - Google Patents

Description

  The present invention divides the periphery of the vehicle body panel into a plurality of small regions and numerically analyzes the flow of electrodeposition liquid and air, and whether or not an electrodeposition liquid pool is generated in the vehicle body after electrodeposition coating pulled up from the electrodeposition tank. The present invention relates to a fluid analysis method around a vehicle body panel for predicting the above.

  In an automobile vehicle, a full dip type electrodeposition coating in which a vehicle body is immersed in an electrodeposition liquid in an electrodeposition tank to electrically attach a paint is common. Such electrodeposition coating has the advantage that the coating film can be made substantially uniform, and the welding portion of the vehicle body can also be coated. The vehicle body detached from the electrodeposition tank is washed with water in the washing process and then heated in an oven in the baking process to finish the undercoating.

The full-dip electrodeposition coating has a drawback that when an air pocket called an air pocket is generated on the inner surface of the hood, the inner surface of the roof, the lower surface of the floor, or the like, a coating cannot be formed on this portion. In order to solve this drawback, a nozzle that discharges the electrodeposition liquid toward the vehicle body is provided in the electrodeposition tank, and the air pocket is moved by the blowing flow from this nozzle so that a coating film is also formed in the air pocket portion. An electrodeposition coating method has been proposed (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 5-86497

  By the way, in the full-dip electrodeposition coating, when the vehicle body is pulled up from the electrodeposition tank, an electrodeposition liquid pool may be generated in a bag-like portion such as a side sill. If this electrodeposition liquid pool occurs, it is difficult to completely wash off the electrodeposition liquid in the bag-like part in the water washing process, so when the vehicle body is heated in the oven, the water boils and the electrodeposition liquid Flows out to the outer surface. As a result, a stripe of the coating film called “secondary sagging” is formed on the surface of the outer plate. Therefore, after the undercoat process, a step of sharpening the stripe portion is provided. Depending on the situation, the car body is processed manually. Thereby, while the consumption of the electrodeposition liquid per vehicle increases, the man-hour in a coating line increases and there exists a problem that manufacturing cost increases. In addition, there is a complication that the shaved coating must be collected and disposed of.

  Therefore, it is conceivable that the position of the electrodeposition liquid reservoir is predicted in advance by numerical calculation based on discretization, and the body panel is subjected to perforation or shape change in advance so that the electrodeposition liquid pool does not occur. However, since the car body is relatively long and complicated, it is necessary to divide the periphery of the car body panel into a large number of small areas, and there is a free surface of air and electrodeposition liquid, which makes calculation of surface tension extremely complicated. Combined with that, the calculation takes a long time. Therefore, the prototype vehicle must be distributed in the electrodeposition tank and the position of the electrodeposition liquid pool must be experimentally grasped and dealt with, resulting in a problem that the cost and schedule required for development increase.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to determine in advance the position of the electrodeposition liquid reservoir in the vehicle body pulled up from the electrodeposition tank in the electrodeposition coating of the vehicle body of the full dip method. Another object of the present invention is to provide a fluid analysis method around a vehicle body panel that can be predicted.

In order to achieve the above object, according to the first aspect of the present invention, a numerical calculation model in which the periphery of the vehicle body panel is divided into a plurality of small regions is constructed on a computer, and the electrodeposition liquid around the vehicle body detached from the electrodeposition tank. And a fluid analysis method for numerically analyzing an air flow, wherein the computer sets the small area within a predetermined range from the vehicle body panel as a fluid area, and sets the small area exceeding the predetermined range as a solid area An initial setting step and an analysis step of numerically analyzing the flow of the electrodeposition liquid and the air for the fluid region are performed .
The “small region” here refers to an element in the analysis by the finite element method, a lattice in the analysis by the difference method, and the like.

According to the first aspect of the present invention, the flow of the electrodeposition liquid and the air is calculated as the fluid region only for the small region within the predetermined range from the vehicle body panel. And since the small area | region exceeding the predetermined range is calculated as a solid, the calculation of the fluid is not performed about this area | region.
Here, the electrodeposition liquid pool after the electrodeposition coating of the body panel in the full dip method is based on whether or not the electrodeposition liquid remaining in the bag-like part or the concave part of the body panel flows downward along the panel surface by its own weight. Depending on whether or not it occurs, it is determined. That is, even if the fluid calculation is not strictly performed up to the region separated from the vehicle body panel, the accuracy of the calculation result is not greatly reduced, and it is sufficient to determine the occurrence of the electrodeposition liquid pool.

Therefore, the small area for calculating the flow of the electrodeposition liquid and the air can be reduced, and the calculation time from the initial state to the convergence state can be dramatically shortened. Thereby, the position of the electrodeposition liquid reservoir can be predicted in a short time by numerical calculation without actually putting the prototype car into the electrodeposition tank.
In addition, when the calculation result that electrodeposition liquid pool occurs is obtained, change to a model in which the body panel is perforated or shape changed, and perform the analysis again to predict the body shape where no electrodeposition liquid pool will occur. Thus, it is possible to promptly feed back the design of the vehicle body. Thereby, the cost and schedule required for vehicle development can be shortened.

  According to a second aspect of the present invention, in the fluid analysis method around the vehicle body panel according to the first aspect, the initial setting step includes a solid setting step in which the entire small region is a solid region, and a step after the solid setting step. And a fluid setting step in which the small region within the predetermined range from the vehicle body panel is used as the fluid region.

  According to the second aspect of the invention, in addition to the operation of the first aspect, all the small regions are collectively defined as a solid and within a predetermined range from the vehicle body panel required for the calculation of the flow of the electrodeposition liquid and the air. By defining only a small area as a fluid, the initial setting can be performed with a minimum number of steps, and the initial setting is simple and easy.

According to a third aspect of the present invention, in the fluid analysis method around the vehicle body panel according to the second aspect, the computer sets the fluid region only to the small region adjacent to the vehicle body panel in the fluid setting step. It is characterized by that.

  According to the invention described in claim 3, in addition to the operation of claim 2, the calculation of the electrodeposition liquid and the air flow is limited to only a small area adjacent to the vehicle body panel, thereby further reducing the calculation time. Can be planned.

The invention according to claim 4, in the vehicle body panel surrounding the method of fluid analysis according to claim 2 or 3, wherein the computer, characterized in that the vehicle body panel and the fixed wall in the solid setting step.
Here, the “fixed wall” refers to a region where numerical calculation is not performed without considering deformation and the like.

  According to the fourth aspect of the invention, in addition to the operation of the second or third aspect, the numerical calculation for the vehicle body panel 1 can be omitted, and the calculation time can be further shortened.

  According to a fifth aspect of the present invention, in the fluid analysis method around a vehicle body panel according to any one of the second to fourth aspects, the initial setting step is the small region that is defined as a fluid region in the fluid setting step. An initial region setting step for setting the region to the electrodeposition liquid, and an initial boundary setting step for setting the boundary with the outside in the fluid region after the initial region setting step to air.

  According to the fifth aspect of the present invention, in addition to the operation of any one of the second to fourth aspects, the boundary between the fluid region and the outside from the state in which the electrodeposition liquid is present around the vehicle body panel as an initial condition. By letting air flow in from this boundary and letting the electrodeposition liquid flow out, it is possible to accurately simulate the state in which the vehicle body is detached from the electrodeposition tank, and a good analysis result can be obtained.

According to a sixth aspect of the present invention, in the fluid analysis method around the vehicle body panel according to the fifth aspect, the analysis step is performed for a predetermined time with respect to the fluid region, and a plurality of parameters for each small region are set. An update process that is continuously updated, and each time each parameter is updated in the update process, an end determination value based on the difference between before and after the update for a predetermined parameter is calculated for each small region, and each end determination A determination step of determining whether the largest value among the values is within a preset allowable range amount, and wherein the computer determines that the maximum value is within the allowable range amount in the determination step Then, the analysis is terminated.

According to the sixth aspect of the present invention, in addition to the action of the fifth aspect, each parameter is continuously updated from the initial state for each small region. The change of each parameter at the time of updating in the area becomes small.
Here, when each parameter is updated, the analysis ends when the largest value among the differences before and after the update of the predetermined parameter in each small region is within the preset allowable range amount. When the state converges, the calculation can be finished accurately.
According to the seventh aspect of the present invention, a numerical calculation model in which the periphery of the vehicle body panel is divided into a plurality of small regions is constructed on a computer, and the flow of the electrodeposition liquid and the air around the vehicle body detached from the electrodeposition tank is numerically analyzed. An initial setting step for causing the computer to set the small region within a predetermined range from the vehicle body panel as a fluid region, and to set the small region exceeding the predetermined range as a solid region; An analysis process for numerically analyzing the flow of electrodeposition liquid and air for a region, and a fluid analysis program around a vehicle body panel for executing the analysis process.

As described above, according to the fluid analysis method or program around the vehicle body panel according to the present invention, the fluid is calculated only for the small region within the predetermined range from the vehicle body panel. Thus, the position of the electrodeposition liquid reservoir can be predicted in a short time by numerical calculation.

  1 to 10 show an embodiment of the present invention. FIG. 1 is a schematic explanatory diagram of a vehicle body painting line, FIG. 2 is a flowchart of a fluid analysis method around a vehicle body panel, and FIG. 3 is divided into a plurality of elements. 4 is an explanatory diagram showing a numerical calculation model around the vehicle body panel, FIG. 4 is an explanatory diagram showing a numerical calculation model in a state where all elements are set in a solid region, and FIG. 5 is an electrodeposition liquid in which elements adjacent to the vehicle body panel are set. FIG. 6 is an explanatory view showing a numerical calculation model of the state, FIG. 6 is an explanatory view showing a numerical calculation model of the state in which the boundary with the outside in the fluid region is air, and FIG. FIG. 8 is an explanatory view showing a model, FIG. 8 is an explanatory view showing a numerical calculation model in a state where an element adjacent to the vehicle body panel is filled with air, and FIG. 9 is an explanatory view showing a numerical calculation model in a state in which the electrodeposition liquid remains. FIG. 10 shows an outline of the fluid analysis apparatus. It is a block diagram.

This fluid analysis method around the body panel numerically analyzes the flow of electrodeposition liquid and air during the electrodeposition coating of an automobile body. First, the car body painting line will be briefly described.
A plurality of vehicle body panels 1 are joined to each other by welding or the like to form a body 2 of an automobile, and as shown in FIG. 1, it is conveyed in a substantially horizontal direction on a painting line while being mounted on a hanger of a conveying device 3. . In the coating line, as a pretreatment for electrodeposition coating, the body panel 1 is subjected to a surface treatment including degreasing, water washing, surface adjustment, film formation, and water washing. Thereafter, as shown in FIG. 1, the body 2 as the vehicle body descends toward the electrodeposition tank 4 and moves substantially horizontally while being immersed in the electrodeposition liquid 5. In this state, paint is deposited on the vehicle body panel 1 by applying voltage to the body 2 and electrodes (not shown) in the electrodeposition tank 4. And the body 2 is pulled up from the electrodeposition tank 4 by the conveying apparatus 3, and the electrodeposition liquid 5 adhering to the vehicle body panel 1 without electrodeposition is removed in the washing process. Thereafter, the body 2 is heated in the oven in the baking process, and the undercoating of the body 2 is completed.

  The fluid analysis method around the body panel according to the present embodiment is a numerical analysis of the flow of the electrodeposition liquid 5 and air 6 around the body 2 detaching from the electrodeposition tank 4, and is a bag-like body like a side sill. The generation state of the electrodeposition liquid pool in the panel 1 can be grasped in a simulated manner. Hereinafter, the fluid analysis method of this embodiment will be described in detail with reference to the flowchart of FIG.

  In the present embodiment, analysis is performed using a finite element method. First, the body panel 1 and its periphery are divided into a plurality of elements 7 to construct a model for numerical calculation (step S1). In the present embodiment, as shown in FIG. 3, the fluid inside the side sill formed in a bag shape having a substantially rectangular cross section is analyzed. The side sill body panel 1 has openings 1a at the top and bottom. Then, the vehicle body panel 1 and the periphery thereof are divided into a plurality of mesh-like elements 7 divided by lines substantially perpendicular to the vertical direction and the horizontal direction in accordance with the cross-sectional shape of the side sill. 3 to 9 illustrate a two-dimensional numerical calculation model corresponding to a cross section of the side surface for the sake of explanation, the numerical calculation model may be two-dimensional or three-dimensional. .

  Next, as shown in FIG. 4, all the elements 7 are set in the solid region (step S2). This step S2 is a fixed setting step. In this embodiment, it is set to iron which is a material of the vehicle body panel 1. Thereafter, as shown in FIG. 5, the element 7 adjacent to the vehicle body panel 1 is set as a fluid region, and the element 7 separated from the vehicle body panel 1 remains in the solid region (step S3). In the present embodiment, the fluid region is set to the electrodeposition liquid 5 as an initial state (step S4). That is, the step S3 constitutes a fluid setting step, and the step S4 constitutes an initial region setting step. This state simulates a state in which the body 2 is immersed in the electrodeposition tank 4 and the periphery of the vehicle body panel 1 is filled with the electrodeposition liquid 5.

  Next, the gravity direction in the numerical calculation model is designated (step S5), and the boundary with the outside in the fluid region is set to air 6 as shown in FIG. 6 (step S6). In this embodiment, the opening 1a formed in the upper part and the lower part of the side sill is the boundary element 7, and these elements 7 are changed to the viscosity coefficient of the air 6. The step S6 is an initial boundary setting step. This state simulates a state in which the outside of the side sill is filled with air and the electrodeposition liquid 5 remains inside the side sill immediately after the body 2 is detached from the electrodeposition tank 4. In steps S1 to S6, the initial state of the numerical calculation model is set, and steps S1 to S6 constitute an initial setting step.

  After the initial setting is completed as described above, the parameters of each element 7 are updated by causing each element 7 to advance by a predetermined time (step S7). This step S7 is an update process. Then, it is determined whether or not a predetermined end condition is satisfied (step S8). If the end condition is not satisfied, the process proceeds to step S5. If the end condition is satisfied, the analysis is ended. This step S8 is a determination step. That is, as long as the termination condition is not satisfied, each parameter of each element 7 is continuously updated, and in steps S7 and S8, analysis is performed to numerically analyze the flow of the electrodeposition liquid 5 and air 6 in the fluid region. It has a process.

  As shown in FIG. 7, when time is updated from the initial setting, the air 6 flows into the side sill from the upper opening 1a, and the electrodeposition liquid 5 flows out from the lower opening 1a to the outside of the side sill. Thus, each parameter is continuously updated for each element 7 from the initial state, and as the time progresses and approaches the steady state, the change of each parameter at the time of updating in each element 7 becomes smaller. As shown in FIG. 8, if the fluid region is finally filled with air 6, the electrodeposition liquid pool is not generated, and if the electrodeposition solution 5 remains in the fluid region as shown in FIG. This is a state where an electrodeposition liquid pool is generated.

  In the present embodiment, every time each parameter is updated in step S8, an end determination value based on the difference between before and after the update for a predetermined parameter is calculated for each element 7, and the most out of the end determination values. It is determined whether the large value is within a preset allowable range amount. Then, when it is determined that the end determination value is within the allowable range amount, the analysis is ended. In the present embodiment, the end determination value is an absolute value of a difference before and after updating a predetermined parameter. Note that the end determination value may be a value obtained by dividing the absolute value of the difference before and after the update by the value before or after the update. In the present embodiment, the parameters used for the end determination are speed, pressure, and material volume fraction, but the end determination may be performed using other parameters.

Thus, in the fluid analysis method around the vehicle body panel 1 of the present embodiment, the flow of the electrodeposition liquid 5 and the air 6 is calculated as the fluid region for the element 7 within the predetermined range from the vehicle body panel 1. Since the element 7 exceeding the predetermined range is calculated as a solid, the fluid is not calculated for this region.
Here, the electrodeposition liquid pool after electrodeposition coating of the vehicle body panel 1 in the full dip method is whether or not the electrodeposition liquid remaining in the bag-like portion of the vehicle body panel 1 flows downward along the panel surface by its own weight. Determines whether or not it occurs. That is, even if the fluid calculation is not strictly performed up to the region separated from the vehicle body panel 1, the accuracy of the calculation result is not greatly reduced, and it is sufficient to determine the occurrence of the electrodeposition liquid pool.

Therefore, the element 7 for calculating the flow of the electrodeposition liquid 5 and the air 6 can be reduced, and the calculation time from the initial state to the convergence state can be dramatically shortened. Thereby, the position of the electrodeposition liquid reservoir can be predicted in a short time by numerical calculation without actually putting the prototype car into the electrodeposition tank 4. In particular, in the present embodiment, the calculation time can be effectively shortened by limiting the calculation of the flow of the electrodeposition liquid 5 and the air 6 to only the element 7 adjacent to the vehicle body panel 1.
In addition, when the calculation result that the electrodeposition liquid pool is generated is obtained, by changing the model to the model in which the body panel 1 is perforated or changed in shape and performing the analysis again, the vehicle body shape in which the electrodeposition liquid pool does not occur is obtained. Predicting and prompt feedback to the design of the body 2 is possible. Thereby, the cost and schedule required for vehicle development can be shortened.

  Further, according to the fluid analysis method around the vehicle body panel 1 of the present embodiment, all the elements 7 are collectively defined as a solid, and a predetermined range from the vehicle body panel 1 necessary for calculating the flow of the electrodeposition liquid 5 and the air 6 is obtained. By defining only the element 7 as a fluid, the initial setting can be performed with a minimum procedure, and the initial setting is easy and easy.

  Further, according to the fluid analysis method around the vehicle body panel 1 of the present embodiment, from the state where the electrodeposition liquid 5 is present around the vehicle body panel 1 as an initial condition, the boundary with the outside in the fluid region is defined as air 6. By causing the air 6 to flow in from the boundary and the electrodeposition liquid 5 to flow out, the state in which the body 2 is detached from the electrodeposition tank 4 can be accurately simulated, and a good analysis result can be obtained.

  Further, according to the fluid analysis method around the body panel 1 of the present embodiment, when each parameter is updated, the largest value among the differences before and after the update of the predetermined parameter in each element 7 is set in advance. Since the analysis ends when the amount is within the allowable range, the calculation can be accurately ended when the steady state is reached.

  FIG. 10 shows an example of a hardware configuration capable of configuring the fluid analysis apparatus 100 that executes this fluid analysis method. As shown in the figure, the fluid analysis apparatus 100 of this embodiment includes a CPU 101, a ROM 102, a RAM 103, a keyboard controller 105 of a keyboard 109, a display controller 106 of a display 110 as a display unit, a hard disk 111, and a flexible device. A disk controller 107 of the disk 112 and a network interface controller 108 for connection to the network 120 are configured to be communicable with each other via the system bus 104.

  The CPU 101 comprehensively controls each component connected to the system bus 104 by executing software stored in the ROM 102 or the hard disk 111 or software supplied from the flexible disk 112. That is, the CPU 101 performs control for realizing the operation of the fluid analysis method according to the present embodiment by reading and executing the processing program from the ROM 102, the hard disk 111, or the flexible disk 112 in accordance with a predetermined processing sequence.

  The RAM 103 functions as a main memory or work area for the CPU 101. A keyboard controller 105 controls an instruction input from a keyboard 109 or a pointing device (not shown). The display controller 106 controls display on the display 110. The disk controller 107 controls access to the hard disk 111 and the flexible disk 112 that store a boot program, various applications, edit files, user files, a network management program, a predetermined processing program in the present embodiment, and the like. The network interface controller 108 transmits and receives data to and from a device or system on the network 120 in both directions.

In addition, although what was analyzed by the finite element method was shown in the said embodiment, you may use other discretization analysis methods, such as a difference method. In the difference method, the area around the vehicle body panel 1 is divided into a lattice shape, and each parameter of the lattice as a small region is updated.
Moreover, in the said embodiment, what showed the body panel 1 periphery divided | segmented into the mesh-like small area | region was shown, However, The shape of a small area | region can be changed suitably according to the shape and calculation method of the vehicle body panel 1. FIG. Of course, not only the bag-like portion of the vehicle body panel 1 as in the above-described embodiment, but also the concave portion can be subjected to numerical calculation in the same manner as in the above-described embodiment.

  Moreover, in the said embodiment, although what analyzed the behavior of the vehicle body panel 1 by making the vehicle body panel 1 into the solid element 7 was shown, you may calculate the vehicle body panel 1 as a fixed wall. In this case, the numerical calculation for the vehicle body panel 1 can be omitted, and the calculation time can be further shortened. Further, the element 7 separated from the vehicle body panel 1 may be calculated as a fixed wall.

  Moreover, in the said embodiment, although what made only the element 7 adjacent to the vehicle body panel 1 a fluid area | region was shown, for example, as shown in FIG. 11, it is 2 from the vehicle body panel 1 side in the numerical calculation model of the said embodiment. You may make it calculate to the 1st element 7 as a fluid area | region. In other words, if the element 7 is a fluid region within a predetermined distance from the vehicle body panel 1 and the element 7 exceeding the predetermined distance is a solid region, the calculation time can be shortened.

  Further, in the above embodiment, the analysis is terminated when the calculated end determination value is within the allowable range amount. However, the air 6 does not reach the steady state, but the air 6 does not reach the surface of the vehicle body panel 1. If the electrodeposition liquid 5 is completely contacted, it may be determined that the electrodeposition liquid 5 does not remain in the side sill, and the analysis may be terminated. In addition, specific details such as the detailed structure may be changed as appropriate. Of course.

It is a schematic explanatory drawing of the coating line of the vehicle body which shows one Embodiment of this invention. It is a flowchart of the fluid analysis method around a vehicle body panel. It is explanatory drawing which shows the numerical calculation model around the vehicle body panel divided | segmented into the some element. It is explanatory drawing which shows the numerical calculation model of the state which set all the elements to the solid area | region. It is explanatory drawing which shows the numerical calculation model of the state which set the element adjacent to a vehicle body panel to electrodeposition liquid. It is explanatory drawing which shows the numerical calculation model of the state which made the boundary with the exterior in the fluid area | region the air. It is explanatory drawing which shows the numerical calculation model of the state advanced from the initial state in time. It is explanatory drawing which shows the numerical calculation model of the state with which the element adjacent to a vehicle body panel was satisfy | filled with air. It is explanatory drawing which shows the numerical calculation model of the state in which the electrodeposition liquid remained. It is a schematic block diagram of a fluid analyzer. It is explanatory drawing which shows the numerical calculation model of the state which set the element in the predetermined range to the fluid area | region from the vehicle body panel which shows a modification.

Explanation of symbols

1 Body panel 2 Body 4 Electrodeposition tank 5 Electrodeposition liquid 6 Air 7 Element

Claims (7)

A fluid analysis method for constructing a numerical calculation model in which the periphery of a vehicle body panel is divided into a plurality of small regions on a computer and numerically analyzing the flow of electrodeposition liquid and air around the vehicle body leaving the electrodeposition tank
The computer is
An initial setting step in which the small region within a predetermined range from the vehicle body panel is a fluid region, and the small region exceeding the predetermined range is a solid region;
Fluid analysis method of a peripheral vehicle body panel, characterized in that to perform an analysis step of numerically analyzing the flow of the electrodeposition solution and air for the fluid region. The initial setting step includes
A solid setting step in which all the small regions are solid regions;
2. The fluid analysis method around the vehicle body panel according to claim 1, further comprising a fluid setting step in which the small region within the predetermined range from the vehicle body panel is the fluid region after the solid setting step. . 3. The fluid analysis method around a vehicle body panel according to claim 2, wherein the computer sets the fluid region only to the small region adjacent to the vehicle body panel in the fluid setting step. The computer, the vehicle body panel surrounding the method of fluid analysis according to claim 2 or 3, characterized in that the vehicle body panel and the fixed wall in the solid setting step. The initial setting step includes
An initial region setting step of setting the small region as the fluid region in the fluid setting step to an electrodeposition liquid;
The vehicle body panel periphery as described in any one of Claim 2 to 4 which has an initial boundary setting process which sets the boundary with the exterior in the said fluid area | region to air after the said initial area setting process Fluid analysis method. The analysis step includes
An update step of continuously updating a plurality of parameters of each small region by proceeding with time for a predetermined time with respect to the fluid region;
Each time each parameter is updated in the updating step, an end determination value based on the difference between before and after the update for a predetermined parameter is calculated for each small area, and the largest value among the end determination values is set in advance. A determination step of determining whether or not the amount is within an allowable range amount,
The computer, the vehicle body panel surrounding the method of fluid analysis according to claim 5, characterized in that the ends and analysis you determined is within the allowable range amount in the determining step. A fluid analysis program for constructing a numerical calculation model in which a periphery of a vehicle body panel is divided into a plurality of small regions on a computer, and numerically analyzing the flow of electrodeposition liquid and air around the vehicle body detached from the electrodeposition tank,
In the computer,
An initial setting step in which the small region within a predetermined range from the vehicle body panel is a fluid region, and the small region exceeding the predetermined range is a solid region;
A fluid analysis program around the vehicle body panel for performing an analysis step of numerically analyzing the flow of the electrodeposition liquid and air for the fluid region.

Images