JPH11219349A - Liquid analysis device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid analysis device which can precisely and integrally correct a generated composite grid to an optimum composite grid. SOLUTION: An auxiliary grid that has a time sequential change boundary condition made into an object and generated in an auxiliary grid generation part 2 is arranged on a main grid generated in a main grid generation part 1. The boundary condition and the physical quantity of the auxiliary grid are changed by the boundary condition which time-sequentially changes. A time sequential boundary condition setting part 9 regenerates the auxiliary grid by the changed boundary condition and physical quantity and the composite grid is generated. Then, repetitive calculation is repeated until a convergence.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid analyzer which can be used for designing a living environment.

[0002]

2. Description of the Related Art In recent years, with the development of large-scale high-speed computers capable of vectorization calculation or simultaneous parallel processing, a plurality of calculation grids have been generated in a large space having complicated boundary conditions, and then a material in the space has been generated. An apparatus that creates a group of equations expressing changes and states of various substances using physical laws governing such changes and solves them using an iterative calculation method is widely used. For example, a flat plate stress analysis device using the finite element method is an example of this device in a broad sense.
And NASTRAN are examples of programs used for this device.

It should be noted that the physical laws, formulas, and techniques that are premised in these analyzes, such as mass conservation law, momentum conservation law, energy conservation law, coordinate conversion, finite difference method and finite element method A method of grid division (mesh division) of a space to be used, a predetermined difference, a determination value used to determine whether or not to perform iterative calculation, a method of giving boundary conditions, a method of iterative calculation when performing iterative calculation,
For a method of solving a group of equations constituting a determinant, a method of simultaneous parallel processing by a large-scale high-speed computer, and the like, see, for example, “Mechanical Engineering Handbook” edited by the Japan Society of Opportunities A5, edited by Fluid Engineering, Information Processing Society of Japan "Information Processing Handbook" published in 1989, Suhas. V. Patanker, Yukio Mizutani, Translated by Shoji Kazuki, "Numerical Analysis of Heat Transfer and Flow by Computer," published in Morikita Publishing and other publications. Etc. and are known technologies. It is also well known to calculate pressure, momentum, mass, heat quantity, and the like, or to calculate correction amounts of those physical quantities. For example, the calorific value of the fluid increases due to the decrease in the momentum, and therefore the density and flow rate must be corrected, and the density and viscosity must be adjusted according to the temperature, pressure, etc. of the fluid required for these calculations. It is a well-known technique to input various physical property values in advance.

[0004] When a fluid analysis is performed by a conventional general analysis apparatus, a target space is divided into a plurality of grids, and a continuous equation, a momentum conservation equation, and an energy conservation equation are provided for each of the grids. Then, a conservation equation of various physical quantities including the heat quantity is established, and then the equations are simultaneously solved.

[0005] At this time, there are places where the external environment and the like change rapidly, such as a diverging section, a merging section, a bending section, and a blowing section. When there is an object that obstructs the flow of air, the grid spacing is made dense for accurate analysis.
In such a case, the grid tends to be denser than necessary, which often leads to an inconvenient situation in terms of storage resources required by the computer and calculation speed. For this reason, attempts have been made to use a superimposed grid method in which sub-gratings with dense grid intervals are arranged only in places where analysis is required with high accuracy, and a composite grid method represented by a local division method.

Next, an example of such an analysis method will be specifically described.

[0007] 1. The shape of the space to be analyzed, the contents of the external force causing the flow, such as the physical property value and flow rate of the internal fluid, and various formulas and physical laws used for the analysis are input via a CRT, a keyboard, and the like.

[0008] 2. The grid division of the space to be analyzed is performed according to a predetermined procedure. In this case, the interval (size) of the main lattice, the interval (size) of the sub-lattice, the arrangement position, and the like are basically specified by the analyst.

3. The priority of selection of the grid to be subjected to the repetitive calculation and the number of repetitive calculations in each grid are input by the analyst.

[0010] 4. Grids with higher priorities, and in many cases, grids near power sources and with boundary conditions are subject to iterative calculations.

5. Equations indicating various states of the fluid in the grid are solved by iterative calculation, assuming some conditions such as the flow velocity in the grid. In many cases, if the number of repetitions reaches a certain value, or if the calculation result and the previous calculation result converge within a predetermined value, the repetition calculation for the grid ends. Then, the calculation result is transferred so as to be used as a boundary condition at the time of repetitive calculation of a grid that is continuous with the grid, that is, has a common end face, and has a low priority in repetitive calculation.

7. Hereinafter, one cycle of iterative calculation for all grids is performed according to the priority order.

8. Based on the above, at the time when the calculation results of all the grids are obtained, whether or not each physical quantity satisfies the formulas and laws of physics used in the analysis, for example, the calculation results obtained in the previous cycle and It is determined whether or not the difference from the calculation result obtained in the current cycle has converged to a predetermined value.

9. If the result converges to a predetermined value, the cycle of the iterative calculation for all the grids ends. If it does not converge, a new cycle of iterative calculations for all grids is started again from the grid of the first priority.

[0015]

However, when these methods are employed, since a plurality of types of sub-lattices are arranged three-dimensionally on the lattice, the boundary between the main lattice and the sub-lattice is not present. It is not possible to disregard conditions and object positions. For this reason, when the previously generated sub-lattice is arranged on the main lattice, the lattice may be corrected in consideration of the lattice boundary conditions and information on the object position. However, it is difficult to modify a previously generated sublattice unless a skilled person. In the normal case, researchers first allocate the main grid and sub-grid to the entire analysis space, determine the boundary conditions, object position, and calculation area of each grid, and then perform orthogonal grid division. .

For this reason, when a place where the flow field is expected to be complicated or a place where an object exists is accurately analyzed by using the sub-grid arranged on the main grid, the shape of the object,
If a sub-lattice to which boundary conditions including arrangement conditions and time-series changes are added is generated in advance, it is desired to realize an analysis device that can accurately perform integrated correction of a composite lattice simply by arranging it on the main lattice. Was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a fluid analysis apparatus capable of accurately correcting a generated composite grid into an optimal composite grid. .

[0018]

In order to achieve the above object, according to the present invention, there is provided a main grid generator for generating a main grid in a space to be analyzed, and a main grid generated by the main grid generator. A sub-lattice generation unit that generates a dense sub-lattice with a different lattice interval, a lattice arrangement unit that partially arranges the sub-lattice on the main lattice, and for each of the main lattice and the sub-lattice,
The physical quantity of the corresponding fluid, a fluid physical quantity analysis unit that calculates based on the given formula and boundary conditions, the pressure distribution calculated by the fluid physical quantity analysis unit, the physical quantity of the fluid such as velocity distribution, and given in advance In addition, based on physical property values and physical laws at each physical quantity of the fluid, a fluid physical quantity correction analysis section that approximately corrects the result of the fluid physical quantity analysis section, and a calculation from the fluid analysis section to the fluid physical quantity correction analysis section is predetermined. In a fluid analysis device comprising: an iterative calculation control unit that repeats the above procedure; and a data transfer unit that exchanges necessary data between the main grid and the sub-lattice. A contact determination unit for three-dimensionally matching the object surface of the sub-lattice to the object surface of the main lattice according to the contact information added to the sub-lattice. A fluid analyzing apparatus according.

According to a third aspect of the present invention, by enlarging or reducing a part or the entirety of the sub-lattice arranged by the lattice arranging unit, each of the physical quantities and the respective boundary conditions given in advance can be obtained. 3. The fluid analyzing apparatus according to claim 2, further comprising a lattice deforming unit that changes the size of the sub-lattice according to a scaling ratio and regenerates the sub-lattice.

Further, according to the present invention, when time-series boundary condition change information that changes in time series is added to the sublattice, a new boundary condition is set according to the time-series boundary condition change information, The fluid analysis device according to claim 1, further comprising a time-series boundary condition setting unit for reconstructing a sub-lattice, if necessary, based on the basis.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an embodiment of a fluid analyzing apparatus according to the present invention. FIG. 2 is a flowchart of the operation.

In FIG. 1, reference numeral 1 denotes a main grid generator for generating a main grid. Reference numeral 2 denotes a sub-lattice generation unit that generates a sub-lattice. Reference numeral 5 denotes a grid arrangement unit for arranging the sub lattice on the main lattice. Reference numeral 6 denotes a part of the grid arrangement unit, which is based on the contact information added to the sub-grating (for example, the air conditioner should make contact with the wall of the room) and the positional relationship between the main grid and the sub-grating object part. , A contact determination unit that determines whether or not the main grid and the sub-lattice object portions are in contact with each other.

Reference numeral 3 denotes an orthogonal grid generation unit that generates an orthogonal grid based on the shape and roughness of the main grid when the sub grid includes curved surface shape information. Reference numeral 4 denotes a grid transformation unit that, when a sub-lattice arranged on the main grid is scaled once, changes physical quantities and boundary conditions according to the scale-up / down ratio and regenerates the sub-lattice.

The main grid generator 1, the sub grid generator 2, and the orthogonal grid generator 3 constitute a grid generator a. The sub-grid deformation unit 4 and the grid placement unit 5 constitute a grid editing unit b.

Reference numeral 7 denotes an analysis unit that calculates a fluid pressure, a velocity based on the law of conservation of momentum, and physical quantities such as temperature and viscosity for each grid in a space to be analyzed. Reference numeral 8 denotes a fluid physical quantity correction unit that approximately corrects the pressure or velocity of the fluid from the pressure distribution and the momentum calculated by the analysis unit 7 based on the law of conservation of mass. When the sublattice has a time-series boundary condition changing unit (not shown), the boundary condition is reset according to the change condition, the sublattice is regenerated according to the changed boundary condition, and the calculation is performed again. This is a time-series boundary condition setting unit to send out to the repetition cycle. Reference numeral 10 denotes an iterative calculation control unit that controls the repetition of various calculations from the analysis unit 7 to the data transfer unit 8 and the repetition of a cycle of a series of such repetitive calculations.

Reference numeral 100 denotes main grid related data, sub grid related data 1, 2, 3,. . . . And is accessed by the grid generation unit a. Reference numeral 200 denotes main grid related data and sub grid related data 1, 2, 3,. . . . . Is connected to the main grid generator 1, the sub grid generator 2, the orthogonal grid generator 3, the grid editor b, the analyzer 7, and the like.

In addition to the above, various input devices, various storage devices, various output devices, and the like are required to perform numerical analysis, but these are not directly related to the gist of the present invention, and are well-known technologies. Therefore, the detailed description is omitted.
The operation of the present embodiment will be described based on FIG.

First, a procedure for generating grid coordinate data from the read main grid data and sub grid data will be described.

The main grid data and the sub grid data are read out from the hard disk 100 into the memory 200, and the main grid generating unit 1 and the sub grid generating unit 2 generate the coordinate data of the main grid and the sub grid (S1, S2). At this time, the data on the hard disk 100 is the object shape, the boundary condition, and the contact class (for example, the side wall, the upper surface of the P plate,...), And does not include the grid coordinate data. When the sub-grid data includes the curved object data, the orthogonal grid generating unit 3 generates orthogonal grid coordinate data according to the curved surface shape based on the roughness of the main grid (S3, S4). Specifically, as shown in FIG. 7, when a sub-lattice having curved object data is arranged with respect to a main grid having a predetermined roughness, the roughness of the main grid is used as a reference, and an integral number of the sub-grids are used. A sub-grid of the size divided into 1 is drawn vertically and horizontally, the shape of the curved surface is transformed into a polygon along the sub-lattice, and the original volume (area in the drawing)
Deform to be the same as FIG. 8 shows a state after the deformation. In the present embodiment, the orthogonal grid generating unit 3 newly generates an object shape by giving a solid physical quantity and a fluid physical quantity to the grid so that the volume of the grid becomes the same at the curved surface shape. However, the method of giving each physical quantity at this time is not limited to this one, but a method of taking an inner method of a curved surface shape (that is, a method of giving a solid physical quantity or the like only to a grid which entirely falls within the curved surface shape), etc. Is also conceivable.

Next, a method for arranging the generated sub lattice on the main lattice will be described. Sub-lattices are arranged on the main lattice,
Alternatively, when moved after being placed once, the grid placement unit 5 adds the three-dimensional position of the sub-lattice on the main grid and the object surface of the main grid, each surface of the sub-lattice, or the object surface. Depending on the contact class, the contact determination unit 6 moves to the position where the main grid, the sub-lattice surface, or the object surface makes contact (S5, S6), and the roughness of the main grid at the moved position causes The sub lattice coordinate data is reproduced (S9). For example,
The back of the air conditioner body of the sub-grid and the lower part of the desk leg should contact the wall and floor of the main lattice respectively, so if you place a sub-grid containing them near the wall or floor, it will be automatically The back of the air conditioner body and the lower part of the desk leg are placed in contact with objects such as the wall surface and floor surface in the main grid. FIG. 3 shows a main lattice and a sub-lattice before arrangement, and FIG. 4 shows a state where the sub-lattice is first arranged on the main lattice. 300 is the air conditioner body 20
And the right side of the main lattice is the wall surface 21. FIG. 5 shows a state in which the rear surface of the air conditioner body 20 automatically comes into contact with the wall surface 21 automatically.

When the sub-lattice is automatically moved in this way, as shown in FIG. 6, the ratio of the roughness of the main lattice to the roughness of the sub-lattice becomes 1: 3 or 3: 1 or less. And then
The grid is finely adjusted (S9).

When the arranged sub-lattice shape is deformed (S7), the physical quantity and the boundary condition are reset by the sub-lattice deformation unit 4 in accordance with the scaling ratio of the scaled sub-lattice (S8). For accurate analysis, the grid is regenerated in accordance with the physical quantities and boundary conditions (S9).

As described above, the procedure for preparing the data required for the analysis is once finished, the data is taken over to the analysis unit 7, and the flow field and other physical quantities in the grid to be calculated are solved (S10). In this case, the end face of each lattice has the calculation order given priority over the lattice and holds the value or the like previously calculated in a predetermined lattice having a common end face. , The momentum conservation equation, the Navier-Stokes equation consisting of the energy conservation equation, etc. are solved. These equations are given in advance by the analyst according to the type of space or fluid to be analyzed. For example, when the fluid is an incompressible fluid such as water, the Navier-Stokes equation or the like is simplified, and the fluid is converted into a formula that can be analyzed by differential coordinate transformation or the like. In addition, in the flow analysis of air blowing and suction from the air conditioner in the indoor space, it is necessary to consider not only the pressure, momentum, and mass but also the amount of heat and the change in pressure and density accompanying the change in the amount of heat. It is indispensable to repeatedly perform the physical quantity correction calculation such as performing the second analysis and further performing the second analysis based on the analysis result.

Next, the data transfer section 8 exchanges necessary data between each main lattice and each sub lattice. As a result, the values of the flow velocity, flow rate, and the like at each end face calculated by each main grid and sub-lattice in which the order of the repetition calculation is prioritized are the adjacent main grids or sub-lattices or the included sub-lattices or inclusive sub-grids whose calculation order is lower. At the time of the repetitive calculation in the main grid to be performed and the repetitive calculation in the next cycle, the boundary values of the grids are set (S11).

The iterative calculation control unit 10 determines the end of the iterative calculation and sets the time-series boundary condition. The end of the iterative calculation depends on whether the calculation result matches the given boundary condition, whether it is not different from the result of the previous cycle, the convergence of the residual of each grid, and the iterative calculation on each grid. Needless to say, the number of cycles and the calculation time are also used as judgment data.

If there is a next time step to be calculated, the analysis calculation is repeated again according to the above-mentioned flow (S10, S11) (S12). When the time step is changed, the iterative calculation control unit 10 determines that the sublattice included in the calculation has a time-series boundary condition object,
If the sublattice has the property that its physical requirements change over time (S14), the condition is reset by the time-series boundary condition setting unit 9, and the sublattice is reproduced according to the condition. (S15). Here, the time step indicates the time at which the calculation is performed. For example, after one second, 2
Seconds, 5 seconds, 10 seconds,. . . . . . At this time, the calculation after 2 seconds considers the calculation result after 1 second. In order to calculate one time step, iterative calculation 2 is usually performed about 200 times. The end of step S13 means that the next calculation time has not been set.

For example, FIGS. 9 and 10 show examples of deformation of the sub-grating. FIG. 9 shows the flow rate of air blown from the air conditioner main body 20 to the arranged sub-grating and the flow rate of air sucked into the air conditioner main body 20. This shows a state in which the boundary conditions of the flow velocity are set (arrows indicate the direction and strength of the flow velocity). FIG. 10 shows that the arranged sub-lattice is enlarged in the y-axis direction because the object shape is simply deformed, and accordingly, the sub-lattice grid is reproduced and the boundary condition is reset (y-axis). (In this case, the blowing velocity is increased in the y-axis direction, the blowing angle is reduced, and the flow velocity is increased.)

As another example, FIG. 11 shows a situation where the boundary conditions shown in the table are set as initial conditions. FIG.
Is the condition that changes the boundary condition (time-series boundary condition)
Indicates a scene where is set as shown in the table. In such a case, the iterative calculation under the conditions shown in FIG. 11 is completed, and before calculating the next time, the boundary conditions are reset to the values shown in the table of FIG. Change of shape,
Regenerate the grid.

That is, the time series boundary condition object is obtained from the repetition cycle, the required time, the main grid,
The necessary flow field and physical quantity are acquired from the sub-lattice, and new physical quantities and boundary conditions are given to the sub-lattice according to the change rule specific to the sub-lattice, and the grid is regenerated. In other words, the time-series boundary condition object means a subroutine having a boundary condition that changes with time and a physical quantity change rule. For example, when the sub-grid includes an air conditioner such as an air conditioner, the change rule incorporates a control rule, acquires the room temperature from a repetitive cycle, and gives the blow-out temperature, blow-out flow rate, and the like to the sub-lattice. Further, it is possible to incorporate various rules such as a ventilation rule for a window, a door, a ventilation fan and the like, and a change rule for a life cycle of a person.

Although the present invention has been described based on the embodiment, for example, the analysis is performed not only for the analysis of the housing environment but also for the analysis of the heat radiation of the electronic equipment and the analysis of the flow around the building. Can be used for analysis. Further, the present invention may be applied to analysis of electromagnetic waves, stress, and the like, instead of fluids such as water and air. In these cases, analysis is performed using governing equations necessary for each analysis.

Each element of the above-described configuration of the present invention may be realized by a dedicated hardware circuit, or may be realized by software using a computer.

When using the computer,
The present invention also includes a medium such as a CDROM in which a program for realizing all or a part of the function of each element or each part is stored.

[0044]

As described above, in the fluid analyzer of the present invention, when the sub-grid is arranged on the main grid,
In order to automatically generate a composite grid from boundary conditions between each grid, object position information, time-series information as objects, etc.,
Unnecessary grid division is omitted, and calculation cost is reduced.

If the main lattice and the sub-lattice are generated in advance, they can be combined and effective utilization of resources can be achieved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of a fluid analysis device according to the present invention.

FIG. 2 is an operation flowchart of the embodiment.

FIG. 3 is a diagram showing an arrangement of a sub-lattice on a main lattice in the embodiment, showing a main lattice and a sub-lattice before arrangement.

FIG. 4 is a diagram showing an arrangement of a sub-lattice on a main lattice in the embodiment, and is a diagram immediately after an arrangement of a sub-lattice on the main lattice.

FIG. 5 is a view showing an arrangement of a sub-lattice on a main lattice in the embodiment, and is a view after a sub-lattice is automatically adjusted to contact a main lattice.

FIG. 6 is a view showing a state in which a sub-grating is finely adjusted in the state of FIG. 5;

FIG. 7 is a diagram showing a case where a sub-lattice includes a curved object in the embodiment.

FIG. 8 is a diagram showing that when a curved sub-lattice is arranged on a main lattice in the embodiment, the sub-lattice is modified to an orthogonal lattice.

FIG. 9 is a diagram showing a sub-lattice before a change when a boundary condition of the sub-lattice changes with time in the embodiment.

FIG. 10 is a diagram showing reconstruction of a sub-lattice after a change when the boundary condition of the sub-lattice changes with time in the embodiment.

FIG. 11 is a diagram showing a sub-lattice before a change in a case where the boundary condition of the sub-lattice changes with time in the embodiment.

FIG. 12 is a diagram showing reconstruction of a sub-lattice after a change when the boundary condition of the sub-lattice changes over time in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main grid generation part 2 Sub lattice generation part 3 Orthogonal lattice generation part 4 Sub lattice deformation part 5 Grid arrangement part 6 Contact judgment part 7 Analysis part 8 Data transfer part 9 Time series boundary condition setting part 10 Iterative calculation control part 20 Air conditioner main body 21 wall 100 hard disk 200 memory

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hisashi Kodama 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] A main lattice generating unit that generates a main lattice in a space to be analyzed; a sub-lattice generating unit that generates a dense sub-lattice having a different lattice interval from the main lattice generated by the main lattice generating unit; Calculating a physical quantity of a corresponding fluid for each of the main grid and the sub-lattice based on a given equation and boundary conditions; The fluid physical quantity analysis unit, based on the physical quantity of the fluid such as pressure distribution and velocity distribution calculated by the fluid physical quantity analysis unit, and a physical property value and a physical law at each physical quantity of the fluid, which is given in advance, based on the fluid physical quantity A fluid physical quantity correction analysis section that approximately corrects the result of the analysis section, an iterative calculation control section that repeats a calculation from the fluid analysis section to the fluid physical quantity correction analysis section in a predetermined procedure, and the main grid and the sub grid Necessary between A data transfer unit that performs transmission and reception of important data, wherein the grid arranging unit transmits the sub-grating to the object surface of the main grid according to contact information added to the sub-grid created in advance. A fluid analysis device comprising a contact determination unit for three-dimensionally matching the object surface of the fluid. 2. When arranging the sub lattice on the main lattice,
An orthogonal lattice generator for regenerating the sub-lattice into an orthogonal coordinate lattice based on surface information added to the sub-lattice created in advance and roughness information of a main lattice to be arranged. Item 3. The fluid analysis device according to Item 1. 3. Enlarging or reducing a part or the whole of the sub-lattice arranged by the lattice arranging unit, thereby changing each of the given physical quantities and each of the boundary conditions according to a scaling ratio. 3. The fluid analyzing apparatus according to claim 2, further comprising a lattice deforming unit for regenerating the sub-lattice. 4. When the time-series boundary condition change information that changes in a time series is added to the sub-lattice, a new boundary condition is set according to the time-series boundary condition change information. 4. The fluid analyzing apparatus according to claim 1, further comprising a time-series boundary condition setting unit for reconstructing a grid. 5. A medium storing a program for realizing all or a part of functions of each part of the fluid analysis device according to claim 1. Description: