JPS6368963A - Method for supporting coordinate lattice generation - Google Patents

Abstract

PURPOSE:To reduce the work time for generating a coordinate lattice, and to generate an optimum coordinate lattice in accordance with a physical phenomenon to be analyzed, by roughening the coordinate lattice which is generated first, and fining the coordinate lattice of a local analyzing area. CONSTITUTION:A coordinate lattice generation support device 1 is provided with an arithmetic processor 4, and to the processor 4, a storage device 5 and an operating board 6 are connected and also, a display device 2 is connected through an image processor 3. A coordinate lattice is generated in the whole analyzing area, the physical quantity of the whole analyzing area is derived by an analysis, and a contour line of the physical quantity is displayed on the device 2. The coordinate lattice in a local analyzing area in the analyzing area which has been set by an analysis worker is generated by taking the derived physical quantity into consideration. By using the coordinate lattice in the local analyzing area, the physical quantity in the local analyzing area is calculated. The coordinate lattice in the whole analyzing area is corrected by using a gradient of the derived physical quantity in the local analyzing area, and using the physical quantity of the whole analyzing area in other area. In this way, the work time required for generating the coordinate lattice is reduced and an optimum coordinate lattice can be generated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for supporting the generation of a coordinate grid for an analysis object in numerical analysis using a computer, and in particular, to a method for supporting the generation of coordinate grids for an analysis target in numerical analysis using a computer. , relates to a coordinate grid generation support method suitable for interactively generating an optimal coordinate grid depending on a physical phenomenon to be analyzed.

(Prior Art) In fields such as structural analysis, fluid analysis, and electromagnetic field analysis, general-purpose numerical analysis programs using the finite element method and the finite difference method have been created, making highly accurate analysis possible.

When designers use these, it takes a lot of time to create input data, so methods and programs have been developed to support the creation of coordinate grids. These methods involve constructing an analysis region in a computer using the shape modeling method, calculating the positions of coordinate grid points using interpolation or interpolation, or the zigzag transformation method, and automatically generating data such as grid point numbering and physical property data. (for example, Nikkei Mechanical,
October 8, 1984 issue, PP.

65-71 introduce various methods and programs). Furthermore, a method is proposed to improve the analysis accuracy by re-correcting the coordinate grid points using the gradient of the physical quantity obtained by the analysis (for example, precision machinery 47
Vol. 4, p. 399-404).

[Problem that the invention attempts to solve]

The conventional technique of re-modifying the coordinate grid using the gradient of the physical quantity obtained by the above analysis takes a method of re-modifying the coordinate grid using the analysis results of the entire analysis area. However, there was a problem in that it was necessary to repeat the calculation of physical quantities for the entire analysis area several times, which increased the calculation time. For two-dimensional problems, there is no particular problem because the calculation time is short, but for three-dimensional problems, the calculation time is five to ten times that of two-dimensional problems, making it difficult to process interactively. There was a bright spot.

SUMMARY OF THE INVENTION An object of the present invention is to provide a coordinate grid generation support method that can reduce work time for coordinate grid generation and easily generate an optimal coordinate grid interactively according to a physical phenomenon to be analyzed.

[Means for solving problems]

The above object is achieved by the following means.

Generate a coordinate grid within the analysis domain to analyze physical phenomena,
The contour lines of the physical quantities are displayed, and then some area within the analysis area is defined as the local analysis area, and 1. Using the obtained physical quantities, a birth grid is created within one local analysis region, taking into account the gradient of the physical quantities. Using the created coordinate grid,
Calculate physical quantities within the local analysis region. Next, in the region excluding the local analysis region from the analysis region, the physical quantities obtained first are used, and in the local analysis region, the physical quantities obtained by the analysis of the local analysis region are used, taking into account the gradient of the physical quantity. , generate a coordinate grid for the entire analysis domain.

As a method for creating a coordinate grid taking into account the gradient of physical quantities, for example, J, U, Brackbill (J, C
omp.

Phys, 46. A method of generating a coordinate grid by minimizing the following functional using the method of pp. 342-368 (1982) may be used.

■=λIII+λ2I2 Here, λl and λ2 are parameters, 11=/ ((Oe)”+(On)”+(03)”)
dQ engineering 2=fWJndΩ ξ, η, 3 are the coordinates of the mapping space, Ω is the analysis region, and W is the distribution of the physical quantity or its gradient.

[Effect]

Among the above methods, the first coordinate grid to be generated is
By making the coordinate grid of the local analysis region finer, the calculation time required for calculating physical quantities can be reduced. In addition, if a region that is important for analysis is taken as a local analysis region, compared to the conventional method of analyzing the entire analysis region using a fine coordinate grid and re-correcting the coordinate grid using the obtained physical quantities. can also generate a coordinate grid that provides the same level of analytical accuracy.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure shows the configuration of a coordinate grid generation support device 1 of the present invention.

The support device 1 includes a display device (for example, CRT) 2, an image processing device 3, an arithmetic processing device (for example, an electronic computer) 4, a storage device 5. It has an operation panel (for example, a keyboard) 6. The display device 2 is connected to the arithmetic processing device 4 via the image processing device 3.
The storage device 5 and operation panel 6 are also connected to the arithmetic processing device 4 .

FIG. 2 shows a flowchart of the processing procedure according to the present invention. This processing procedure is as follows.

(1) Create a coordinate grid over the entire analysis area.

(2) The physical quantities of the entire analysis region are determined by analysis, and the contour lines of the physical quantities are displayed on a display device.

(3) Generate a coordinate grid within the local analysis area within the analysis area set by the analysis operator, taking into account the physical quantities obtained in (2) above.

(4) Calculate physical quantities within the local analysis region using the coordinate grid obtained in (3) above and the analysis results obtained in (2) above as boundary conditions.

(5) In the local analysis region, use the gradient of the physical quantity obtained in (4) above, and in other regions.

The coordinate grid of the entire analysis area is corrected using the physical quantities obtained in (2) above.

As described above, according to this embodiment, by viewing the contour lines in (2) above, the analysis operator can locally identify areas that are important for analysis (areas with dense contour lines) even if he or she does not have sufficient experience in analysis work. Can be set as an analysis area.

In addition, the coordinate grid generated in (1) above is coarsened, and the coordinate grid generated in (1) above is
By making the coordinate grid generated in step 3) finer, it is possible to generate a coordinate grid that is optimal for analyzing physical phenomena without increasing calculation time.

〔Effect of the invention〕

According to the present invention, it is possible to easily create a coordinate grid according to the physical phenomenon to be analyzed, thereby reducing the working time required to generate the coordinate grid and improving the accuracy of numerical simulation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a coordinate grid generation support device of the present invention, and FIG. 2 is a diagram showing a processing procedure of the present invention. 1... Coordinate grid generation support device, 2 River display device, 3...
・Image processing device, 4...Arithmetic processing unit,...Storage device, Haya 1 figure et al. 11 躬2-Figure

Claims (1)

[Claims] 1. A coordinate grid generation support method for creating an optimal coordinate grid for a target analysis area in order to analyze a physical phenomenon using a computer, comprising: generating the coordinate grid within the analysis area. a first step of calculating a physical quantity using the coordinate grid and displaying its contour line; and a part of the area within the analysis area is set as a local analysis area, and the first step is performed within the local analysis area. A second step of generating the coordinate grid according to the obtained physical quantities, and analyzing the physical quantities in the local analysis area using the results obtained in the first step as boundary conditions of the local analysis area. In the third step, in the local analysis area, according to the physical quantity obtained in the third step, and in the area excluding the local analysis area from the entire analysis area, according to the physical quantity obtained in the first step. a fourth step of generating the coordinate grid according to the coordinate grid.