JPS63656A - Supporting method for generation of coordinate grid - Google Patents

Abstract

PURPOSE:To easily generate a coordinate grid suitable for analysis, by displaying a contour line of the physical quantity obtained by a numerical simulation simultaneously with the coordinate grid, on an analysis area on a mapping space screen on a display device. CONSTITUTION:A coordinate grid generation supporting device 1 supports generation of a coordinate grid by a numerical analysis simulation, and provided with display devices 2A, 2B, image display control devices 3, 5, an arithmetic processing unit (for instance, an electronic computer) 7, an operating board (for instance, a keyboard) 9, and an external storage device 8. A real space screen and a mapping space screen are set onto the display devices 2A, 2B, the coordinate grid is generated by a coordinate converting method, thereafter, a contour line of the physical quantity obtained by the numerical analysis simulation is displayed simultaneously with a coordinate grid line onto the mapping space screen, therefore, whether the physical phenomenon is the coordinate grid being suitable for an analysis or not can be decided by seeing the mapping space screen.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a coordinate grid generation support method and apparatus, and in particular, to whether the generated coordinate grid is the optimal coordinate grid for the physical phenomenon to be analyzed. The present invention relates to a coordinate grid generation support method suitable for determining whether , or not.

[Conventional technology]

In fields such as structural analysis, fluid analysis, and electromagnetic field analysis, general-purpose numerical analysis codes using finite element methods and finite difference methods have been created, making highly accurate analysis possible. However, when designers try to analyze physical phenomena using these analysis codes, they need to generate coordinate grids, number them, and calculate nodal coordinates.

There is a problem in that most of the analysis work time is spent creating data such as physical property data. Especially in 3D analysis.

80-90% of analysis work time is spent on data creation.

Therefore, in order to save labor in creating this data.

Various types of briprocessors have been developed. Taking as an example a finite element method mechanical system CAE processor (for example, the shape modeling system section of the CAE system introduced in Journal of the Japan Society of Mechanical Engineers Vol. 88, No. 794, PP29-35), the graphic display can be displayed online. It is used interactively to construct the geometry of the object to be analyzed in the computer, and based on this.

Determine the shape surface and internal coordinate grid points by interpolation,
Automatically generate data such as coordinate grid generation, numbering, and physical property data. In the conventional method, the analysis area itself was displayed on the graphic display, and data such as the number of mesh points, mesh concentration points, and physical property data was input by picking the displayed shape with a light pen, etc. . In order to obtain a satisfactory solution within the calculation time using the limited memory capacity of a computer, it is necessary to concentrate meshes on areas that are important for analysis and sparse them on areas where physical quantities change little. , such a mesh partition is created interactively in the preprocessor.

[Problem that the invention seeks to solve]

In conventional methods, when the object to be analyzed has a complex shape, it is necessary to use a physical model (e.g., flow velocity gradient in fluid analysis, stress concentration in structural analysis, electric field, magnetic field strength in electromagnetic field analysis, etc.). This is a case where it is difficult to intuitively understand the object to be analyzed by looking at it. In this case, the S standard grid that is considered optimal for analysis (for example, streamlines in fluid analysis,
It is difficult to generate coordinate grids along lines of equal stress in structural analysis and along lines of electric or magnetic force in electromagnetic field analysis, and because the coordinate grid is inappropriate, simulation results using numerical analysis codes may not be satisfactory. .

An object of the present invention is to provide a coordinate grid generation support method and apparatus that allow an analysis operator to easily determine whether or not a coordinate grid is suitable for the physical phenomenon to be analyzed when generating a coordinate grid for use in numerical simulation. It is about providing.

[Means for solving problems]

The above object is achieved by displaying the contour lines of the physical quantities obtained by numerical simulation simultaneously with the coordinate grid on the analysis region on the mapping space screen on the display device.

[Effect]

After setting the real space screen and mapping space screen on the display device and creating a coordinate grid using the coordinate transformation method.

The contour lines of the physical quantities obtained through the numerical analysis simulation are displayed on the mapping space screen at the same time as the coordinate grid lines, so you can easily check whether the coordinate grid is suitable for analyzing physical phenomena by looking at the mapping space screen. can be judged.

〔Example〕

Preferred embodiments of the invention are described below. FIG. 1 shows the coordinate grid generation support device of this embodiment. Coordinate grid generation support device! ! ! 1 supports generation of a coordinate grid in numerical analysis simulation, and includes display devices 2A and 2B, image display control devices 3 and 5. Arithmetic processing unit f!
I: (for example, W1 child computer) 7. Operation panel (for example, keyboard) 9. and an external storage device 1't8. Of course, a display device in which input is performed using a light pen may be used.The image display control device 3 includes an image data storage section 4 and is connected to the display device 2A.

Further, the image display device [5 includes a one-image data storage section 6.

It is connected to display device M2B. The arithmetic processing device 7 includes a calculation section 7a, a processing procedure storage section 7b, and an intermediate data storage section 7c.
, an input section 7d, a coordinate grid data output section 7θ2, and image data input/output sections 7f and 7g. The processing procedure storage unit stores the processing procedures for coordinate grid calculation using the coordinate transformation method and numerical simulation of physical quantities.The 0 image display devices e13 and 5 are connected to the 1 image data output units 7f and 7g. The external storage device 8 stores calculated values of coordinate grid data. External storage! 8 is connected to the coordinate grid data output section 7e.

FIG. 2A and FIG. 3B show a real space screen and a mapping space screen of the coordinate grid generated according to the present invention, respectively.

The numbers above indicate the corresponding vertices in the 1-ryo diagram. The coordinate values of the coordinate grid are calculated by the coordinate transformation method using such a correspondence between the analysis regions in the real space and the mapping space.

The coordinate transformation method is a method that makes a one-to-one correspondence between coordinates x, y, and z in real space and coordinates ξ, η, and ζ in mapping space.

That is, x=f(ξ, η
, ζ) w y=g (ξ, η, ζ).

-f* gt h, which refers to a -to-one correspondence such as z=h(ξ, η, ζ), does not have to be an explicitly expressed function, for example.

etc. may be solved numerically.

Figures 3A and 3B show an example in which a coordinate grid is generated using a simplified model and correspondence between vertices on a mapping space that is different from those shown in Figures 2A and 2B, and shows a real space The coordinate grid on the screen is very different.

Figures 4A and 4B show that physical quantities (e.g., temperature, electric field, etc.) are calculated by a numerical simulation program using the coordinate grid explained in Figures 2A and 2B, and the contour lines are mapped to the real space screen. In Figure 8, which is displayed on a spatial screen, solid lines indicate coordinate grid lines, and broken lines indicate contour lines of physical quantities.

Figures 5A and 5B use the coordinate grid explained in Figures 3A and 3B to calculate the physical quantities for the same phenomenon as in Figure 4, and plot the contour lines on the real space screen and the mapping space screen. This is what is displayed. As can be seen from FIGS. 4B and 5B, the first contour line in the example of FIG. 5B is more parallel to the coordinate grid line than in FIG. 4B, and the spacing between the contour lines is less dense. Therefore, by looking at the mapping space screen, it can be easily seen that the coordinate grid as shown in FIG. 5 is suitable for analyzing physical phenomena. In this way, after determining a simplified model of the analysis region on the mapping space, detailed analysis is performed by increasing the number of grid divisions, thereby making it possible to perform highly accurate analysis. Second
Although the two-dimensional analysis area has been described in FIGS. 5 through 5, it can be easily extended to a three-dimensional analysis area.

〔Effect of the invention〕

According to the present invention, the analysis operator can easily determine that the more parallel the contour lines are to the coordinate grid lines, and the more uniform the density of the contour lines, the more suitable the coordinate grid is for the analysis. If it is determined that the coordinate grid is unsuitable for the analysis, by repeating the process of generating the coordinate grid, a coordinate grid suitable for the analysis can be easily created regardless of the experience of the analysis operator. , can be analyzed with high accuracy.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a coordinate grid generation support device according to an embodiment of the present invention, Figs. 2 and 3 are explanatory diagrams of a coordinate grid generation method using a coordinate transformation method, and (A) and (B) are The coordinate grid diagrams of FIGS. 4 and 5 on the real space screen and the mapping space screen, respectively, are diagrams in which coordinate grid lines and contour lines of physical quantities are simultaneously displayed on the mapping space screen of (B). 1...Coordinate grid generation support device.

Claims (1)

[Claims] 1. In order to analyze a physical phenomenon using a computer, there is a first input step of inputting the shape data of the analysis region using a real space screen, and a simplified shape model of the real space screen is input using a mapping space screen. a second input step of inputting, a first calculation step of calculating coordinate values of a coordinate grid by a coordinate transformation method, and a first display of displaying the calculated coordinate grid points on the real space screen and the mapping space screen. step, a second calculation step of calculating a physical quantity using the calculated coordinate values of the coordinate grid, a second display step of displaying contour lines of the physical quantity on the real space screen and the mapping space screen, and this analysis. A coordinate grid generation support method comprising the step of optimizing the arrangement of the coordinate grid within a region.