High-speed maglev train geometric model modeling method based on SolidWorks

Abstract

The invention discloses a high-speed maglev train modeling method based on SolidWorks, and the method comprises the steps: employing a modeling logic from bottom to top, taking the three-view scanning data of a high-speed maglev train model as a starting point, and carrying out the partitioning processing of the surface of a whole train; respectively creating an end point of each partition; drawing a space curve for the contour of each partition; drawing a spatial curved surface according to the profile curve of each partition; checking the connection condition and the topological structure of each curved surface, and carrying out geometric repair on the gap; performing symmetric treatment on the curved surface; and finally, filling into a high-speed maglev train geometric model. According to the method, the bottom-to-top modeling logic from point to line to surface is used, so that the number of steps for modifying the geometric model can be reduced; more high-quality scanning curved surfaces and boundary curved surfaces can be created, and the number of low-quality contour curved surfaces is reduced; the problem of left-right asymmetry of the model caused by errors can be avoided, influence on follow-up dynamic numerical simulation is avoided, meanwhile, modeling steps can be simplified, and the workload of constructing a geometric model is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of rail transportation, in particular to a geometric modeling method for dynamic numerical simulation of unsteady flow fields. Background Art

[0002] The progress of science and technology has promoted the great development of high-speed railways. With the continuous increase in the operating speed of high-speed trains, people's pursuit of higher-speed land transportation has intensified. As a result, high-speed maglev trains came into being. Ordinary high-speed wheel-rail trains have inevitable aerodynamic problems, so the aerodynamic problems of maglev trains running at ultra-high speeds will be more prominent. Therefore, it is necessary to study the aerodynamic problems encountered by high-speed maglev trains.

[0003] In the absence of standards and measured data, the research on the above issues is mainly based on the computational fluid dynamics (CFD) method. The CFD method refers to the use of computers to use numerical methods to discretize and solve fluid mechanics control equations, so as to achieve the purpose of predicting the regular characteristics of the flow field. The first step in CFD numerical calculation is to establish a train model. A high-quality model can not only improve the accuracy of the simulation results, but also reduce the calculation time. The current mainstream rail transit multi-body dynamics modeling software at home and abroad include Universal Mechanism, SolidWorks, CATIA, etc., among which SolidWorks has the advantages of strong versatility and high modeling accuracy. Summary of the invention

[0004] In response to the above-mentioned prior art, the present invention provides a high-speed maglev train modeling method based on SolidWorks. The method can establish a geometric model according to the actual situation during train operation, establish a parent-child relationship based on the existing characteristics of the vehicle, simplify the modeling process, and facilitate the modification of the overall design parameters of the geometric model or the shape of detailed parts for lateral comparative analysis in dynamic numerical simulation.

[0005] In order to solve the above technical problems, the present invention proposes a high-speed maglev train modeling method based on SolidWorks, which adopts bottom-up modeling logic, takes the three-view scanning data of the high-speed maglev train model as the starting point, and partitions the surface of the whole train; creates endpoints of each partition respectively; draws space curves for the contours of each partition respectively; draws space surfaces from the contour curves of each partition respectively; checks the connection status and topological structure of each surface, and geometrically repairs the gaps; symmetric processes the surface; and finally fills the space surface processed as above into a high-speed maglev train geometric model.

[0006] Furthermore, the SolidWorks high-speed maglev train geometric modeling method of the present invention comprises the following steps:

[0007] Step 1: Zoning of the vehicle surface: Import the three views of the vehicle as sketch images into the base plane of SolidWorks, and divide the vehicle surface into multiple areas. The division basis is as follows: the vehicle is divided into two symmetrical groups of areas along the horizontal center line, and each car section is divided separately in the radial direction. In addition, the plane is divided separately, and the surface with non-tangent boundaries is divided separately. Select all the partitions on the left side of the horizontal center line as the drawing area.

[0008] Step 2: Create endpoints: Select a partition in the drawing area and create endpoints for the boundaries of the partition on the reference plane. The number of endpoints on a reference plane of the partition should not be greater than 4, otherwise the partition should be re-partitioned based on step 1.

[0009] Step 3: Create contour lines: Select the partition described in step 2 and connect the endpoints on the reference plane. The connection method is based on the vehicle design parameters. The straight line boundary is connected by line segments, and the curved boundary is connected by spline curves, so that the spline curve coincides with the corresponding boundary of the partition on the reference plane.

[0010] Step 4: Create a spatial curve: Select a contour line on the front view reference plane and the corresponding contour line on the right view reference plane in step 3 to create a projection curve of the sketch on the sketch, adjust the viewing angle to face the top view reference plane, if the projection curve coincides with the boundary on the top view reference plane, it is considered that the correct spatial curve is obtained, repeat step 4 to obtain the spatial curve corresponding to all contour lines; if the projection curve does not coincide with the boundary on the top view reference plane, return to step 3 to recreate the contour line.

[0011] Step 5: Create a space surface: Select all the space curves in step 4, select the boundary type according to the geometric features of the model, and create a space surface. If a sweep surface can be created, select the sketch contour and open path to create the sweep surface; otherwise, use the space curve as the boundary to create a boundary surface; if a boundary surface cannot be created, create a filled surface.

[0012] Step 6: Create adjacent partition space surfaces: Select adjacent partitions and repeat steps 2 to 5 until all partitions in the drawing area have completed the creation of space surfaces.

[0013] Step 7: Stitch surfaces and create entities: Select all the spatial surfaces obtained in the above steps, use the surface stitching function, check the Create Entity option, and the default stitching tolerance is 0.0025mm.

[0014] Step 8: Mirror entity: Select the spatial surface at the midline as the mirror reference plane, mirror the entity obtained in step 7, and check the options of Merge entity and Stitch surface. The geometric model file can be exported for subsequent numerical simulation calculations.

[0015] The selection of boundary type according to the geometric features of the model described in step 5 is: if the partition has a tangent relationship with the adjacent partition, the common space curve needs to be selected to be tangent to the surface; if the partition boundary is on the center line, the boundary curve needs to be selected to be perpendicular to the contour.

[0016] Specifically, the boundary types include perpendicular to the contour, direction vector, tangent to the face, and curvature to the face.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The method of the present invention is a proportional model established according to the actual model of a high-speed maglev train, which mainly includes surface partitioning processing, creating spatial endpoints, curves, surfaces, stitching surfaces and mirror entities. Using the bottom-up modeling logic from point to line and then to surface, in the subsequent numerical simulation research process, the number of steps for modifying the parameters of the detailed parts of the geometric model and rebuilding the model can be reduced. Before modeling, the body surface is divided into multiple partitions, and the number of endpoints of each partition is controlled, and then the number of spatial curves of each partition is controlled, so that more high-quality scanning surfaces and boundary surfaces can be created, and the number of low-quality contour surfaces can be reduced. Utilizing the symmetry of the actual model of the high-speed maglev, one side of the midline symmetry plane is used as the drawing area, and the other side is obtained through the entity mirroring function. Compared with the overall modeling of the whole vehicle, the left-right asymmetry problem of the model caused by errors can be avoided, and the impact on the subsequent dynamic numerical simulation can be avoided. At the same time, the modeling steps can be simplified and the workload of constructing the geometric model can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the drawing area and surface partitioning

[0020] Figure 2 Illustration of the creation of endpoints, contour lines and space curves

[0021] Figure 3 Schematic diagram of creating a space surface

[0022] Figure 4 The geometric model established for the present invention is shown in FIG.

[0023] Specific implementation methods

[0024] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention in any way.

[0025] The method for modeling a high-speed maglev train geometric model based on SolidWorks of the present invention comprises the following steps:

[0026] Step 1: Surface treatment of the whole vehicle: Figure 1 As shown in the figure, the vehicle surface is divided into multiple areas. The basis for division is as follows: the vehicle is divided into two symmetrical groups along the center line in the horizontal direction, and each car is divided into separate areas in the radial direction. In addition, the plane is divided into separate areas, and the surface with non-tangent boundaries is divided into separate areas. Select all the areas on the left side of the center line in the horizontal direction as the drawing area.

[0027] Step 2: Create an endpoint: Figure 2 As shown, on the front view reference plane and the top view reference plane, create endpoints for the boundary of this partition, that is, Figure 2 Medium gray endpoint.

[0028] Step 3: Create contour lines: Figure 2 As shown, select the partition described in step 2, and connect the endpoints on the front view reference plane and the top view reference plane. Use line segments to connect the straight line boundaries, and use spline curves to connect the curve boundaries, so that the spline curves coincide with the corresponding boundaries of the partitions on the reference plane.

[0029] Step 4: Create space curves: Figure 2 As shown, select a contour line on the front view reference plane and the corresponding contour line on the right view reference plane described in step three to create a projection curve of the sketch on the sketch, adjust the viewing angle to face the top view reference plane, if the projection curve coincides with the boundary on the top view reference plane, it is considered that the correct spatial curve is obtained, repeat step four to obtain the spatial curves corresponding to all contour lines; if the projection curve does not coincide with the boundary on the top view reference plane, return to step three to recreate the contour line.

[0030] Step 5: Create a space surface: Figure 3 As shown, select all the space curves in step 4 to create a boundary surface. Select the boundary that is tangent to the adjacent partition and set it to be tangent to the face; select the boundary on the midline and set it to be perpendicular to the profile. If a sweep surface can be created, select the sketch profile and open path to create the sweep surface; if a boundary and a sweep surface cannot be created, create a fill surface.

[0031] Step 6: Create adjacent partition space surfaces: Select adjacent partitions and repeat steps 2 to 5 until all partitions in the drawing area have completed the creation of space surfaces.

[0032] Step 7: Stitch surfaces and create entities: Select all the spatial surfaces obtained in the above steps, use the surface stitching function, check the Create Entity option, and the default stitching tolerance is 0.0025mm.

[0033] Step 8: Mirror entity: Figure 4 As shown in the figure, select the spatial surface at the midline as the mirror reference plane, mirror the entity obtained in step 7, and check the options of merging entities and stitching surfaces. The geometric model file can now be exported for subsequent numerical simulation calculations.

[0034] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can make many modifications without departing from the purpose of the present invention, all of which are within the protection of the present invention.

Claims

1. A high-speed maglev train modeling method based on SolidWorks, characterized in that: The surface of the train is divided into zones; endpoints of each zone are created respectively; spatial curves are drawn for the contours of each zone respectively; spatial surfaces are drawn from the contour curves of each zone respectively; the connection and topological structure of each surface are checked, and the gaps are geometrically repaired; the surface is symmetrically processed; finally, the spatial surface processed as above is filled into the geometric model of the high-speed maglev train.

2. The high-speed maglev train modeling method based on SolidWorks according to claim 1, characterized in that: SolidWorks geometry modeling software is used, and the following steps are included: Step 1: Zoning of the vehicle surface: Import the three views of the vehicle as sketch images into the base plane of SolidWorks, and divide the vehicle surface into multiple areas. The division basis is as follows: the vehicle is divided into two symmetrical groups of areas along the horizontal center line, and each car section is divided separately in the radial direction. In addition, the plane is divided separately, and the surface with non-tangent boundaries is divided separately; select all the partitions on the left side of the horizontal center line as the drawing area; Step 2: Create endpoints: Select a partition in the drawing area, and create endpoints on the boundary of the partition on the reference plane; the number of endpoints on a reference plane of the partition should not be greater than 4, otherwise the partition should be re-partitioned based on the basis of step 1; Step 3: Create contour lines: Select the partition described in step 2, and connect the endpoints on the reference plane; the connection method is based on the vehicle design parameters, and the straight boundary is connected by line segments, and the curved boundary is connected by spline curves, so that the spline curve coincides with the corresponding boundary of the partition on the reference plane; Step 4: Create a space curve: Select a contour line on the front view reference plane and the corresponding contour line on the right view reference plane in step 3 to create a projection curve of the sketch on the sketch, adjust the viewing angle to face the top view reference plane, if the projection curve coincides with the boundary on the top view reference plane, it is considered that the correct space curve is obtained, repeat step 4 to obtain the space curve corresponding to all contour lines; if the projection curve does not coincide with the boundary on the top view reference plane, return to step 3 to recreate the contour line; Step 5: Create a space surface: Select all the space curves in step 4, select the boundary type according to the geometric features of the model, and create a space surface; if a sweep surface can be created, select the sketch contour and open path to create the sweep surface; otherwise, use the space curve as the boundary to create a boundary surface; if a boundary surface cannot be created, create a filled surface; Step 6: Create adjacent partition space surfaces: Select adjacent partitions and repeat steps 2 to 5 until all partitions in the drawing area have completed the creation of space surfaces; Step 7: Stitch surfaces and create entities: Select all the spatial surfaces obtained in the above steps, use the surface stitching function, check the Create Entity option, and the default stitching tolerance is 0.0025mm; Step 8: Mirror entity: Select the spatial surface at the midline as the mirror reference plane, mirror the entity obtained in step 7, and check the options of merging entities and stitching surfaces; the geometric model file can now be exported for subsequent numerical simulation calculations.

3. The high-speed maglev train modeling method based on SolidWorks according to claim 2 is characterized in that: The selection of boundary type according to the geometric features of the model described in step 5 is: if the partition has a tangent relationship with the adjacent partition, the common space curve needs to be selected to be tangent to the surface; if the partition boundary is on the center line, the boundary curve needs to be selected to be perpendicular to the contour.

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