A structure-unstructured mixed data exchange method, system and device
By employing a transition layer method that combines unstructured mesh wrapping and structured mesh intersection in a jet-disrupted flow field, the problems of local discontinuity in the flow field and low efficiency of the transition layer unit are solved, achieving efficient data exchange and computation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA ACAD OF AEROSPACE AERODYNAMICS
- Filing Date
- 2023-12-28
- Publication Date
- 2026-07-07
AI Technical Summary
Existing technologies have insufficient adaptability of structured meshes when simulating complex jet flow fields, resulting in difficult and time-consuming mesh generation. Furthermore, the structured/unstructured hybrid algorithm suffers from local discontinuities in the flow field when enclosed by complex three-dimensional shapes, leading to low efficiency of transition layer units.
An unstructured mesh is used for body wrapping, and then a structured mesh is used to wrap the body. A transition layer is extended at the interface, which is divided into two transition layers. The center coordinates of the mesh cells are named and marked to realize data exchange and assignment of computational information.
It solves the problem of local discontinuities in the flow field, improves computational efficiency, reduces the time spent searching for transition layer units globally, and enhances computational accuracy and efficiency.
Smart Images
Figure CN117763735B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an optimization method for data exchange using a hybrid structured / unstructured algorithm, belonging to the field of CFD technology. Background Technology
[0002] Reaction control systems (RCS) utilize the reaction force generated by engine jets to rapidly alter the attitude or trajectory of an aircraft. Their role is to compensate for insufficient aerodynamic control surface efficiency and to quickly change flight states, showing broad engineering application prospects. When the RCS jet enters a hypersonic external flow, it interacts with the external flow, forming a complex shock / boundary layer disturbance flow field containing various flow phenomena such as boundary layer separation and reattachment, shock waves, expansion waves, Mach disks, and shear layers. This generates aerodynamic / thermal disturbances that vary strongly nonlinearly with jet parameters, flight conditions, and configuration.
[0003] In engineering applications, it is required to simulate such complex disturbance flow fields as accurately as possible and extract the aerodynamic / thermal changes caused by the disturbance as inputs for control system design to ensure design accuracy. Therefore, structured meshes are generally used to simulate jet disturbance flow fields. However, with the continuous development of aircraft technology, aircraft shapes are becoming increasingly complex. Structured meshes have poor adaptability to complex geometric configurations, and their disadvantages of difficult and time-consuming mesh generation are becoming more and more obvious. Therefore, the need to develop structured / unstructured hybrid mesh technology is becoming more and more urgent.
[0004] Traditional structured / unstructured hybrid methods treat structured meshes as a special case of unstructured meshes, that is, they transform structured meshes into unstructured mesh data structures and then use unstructured mesh solvers for numerical calculations. This does not actually give full play to the advantages of structured meshes. This hybrid method at only the mesh level is not suitable for calculating jet interference flow fields with high accuracy requirements. Summary of the Invention
[0005] The technical problem solved by this application is to overcome the shortcomings of the prior art and provide a structured-unstructured hybrid data exchange method, system and device, which solves the problems of local discontinuity in the flow field when the original structured / unstructured hybrid algorithm data exchange method is applied to three-dimensional complex shape wrapping and the problem of low efficiency in finding transition layer units in the global range when the mesh amount is large.
[0006] The technical solution provided in this application is as follows:
[0007] Firstly, a hybrid structured-unstructured data exchange method is provided, including:
[0008] The unstructured mesh is used to wrap the aircraft to generate a body-fitting unstructured mesh, and then a structured mesh is used to wrap the unstructured mesh.
[0009] Based on the interface between the structured and unstructured meshes, a specified number of layers are extended in the direction away from the unstructured mesh as a transition layer. The transition layer also includes the vertices where the unstructured mesh and the structured mesh intersect.
[0010] The transition layer is divided into two layers: the layer closest to the unstructured mesh is the outer layer of the transition layer, and the layer closest to the structured mesh is the inner layer of the transition layer. The inner layer of the transition layer completely encloses the outer layer of the transition layer.
[0011] The transition layer and the original unstructured mesh portion are output as unstructured meshes for the unstructured solver to read and calculate, thereby obtaining the flow field information of the unstructured mesh; the original structured mesh portion is output for the structured solver to read and calculate, thereby obtaining the flow field information of the structured mesh.
[0012] The unstructured mesh and the structured mesh are mapped according to the transition layer;
[0013] Based on the correspondence between the unstructured mesh and the structured mesh in the transition layer, the flow field information calculated by the structure solver in the transition layer is assigned to the unstructured solver, and the flow field information calculated by the unstructured solver in the transition layer is assigned to the structure solver.
[0014] Update the flow field information of the structured mesh and the unstructured mesh.
[0015] The transition layer, which is divided into two layers, is named as follows: the layer closer to the unstructured mesh in the transition layer is named the outer layer of the transition layer, and the layer closer to the structured mesh in the transition layer is named the inner layer of the transition layer.
[0016] The step of mapping unstructured meshes and structured meshes in the transition layer includes:
[0017] Based on the names of the outer and inner layers of the transition layer, obtain the center coordinates of the mesh cells of the outer and inner layers of the transition layer in the structural solver;
[0018] Based on the condition that the center coordinates of overlapping mesh cells are equal, the center coordinates of the mesh cells in the structure solver for the outer and inner layers of the transition layer are found and marked.
[0019] The specified number of layers is not less than 2.
[0020] The inner and outer layers of the transition layer are separated by an interface, which is an offset surface at the junction between the structured mesh and the unstructured mesh.
[0021] Secondly, a structured-unstructured hybrid data exchange system for jet interference problems is provided, including:
[0022] The mesh generation module uses an unstructured mesh to wrap the aircraft, generating a body-fitting unstructured mesh, and then uses a structured mesh to wrap the unstructured mesh.
[0023] The transition layer selection module extends a specified number of layers in the direction away from the unstructured mesh as a transition layer based on the interface between the structured and unstructured meshes. The transition layer is divided into two layers: the layer closer to the unstructured mesh is the outer layer of the transition layer, and the layer closer to the structured mesh is the inner layer of the transition layer.
[0024] The naming module names the layer in the transition layer closest to the unstructured mesh as the outer layer of the transition layer, and the layer in the transition layer closest to the structured mesh as the inner layer of the transition layer.
[0025] The corresponding module obtains the center coordinates of the mesh cells in the structural solver based on the naming of the outer and inner layers of the transition layer; based on the condition that the center coordinates of the overlapping mesh cells are equal, it finds and marks the center coordinates of the mesh cells in the non-structural solver based on the center coordinates of the outer and inner layers of the transition layer in the structural solver, thus obtaining the correspondence.
[0026] The mesh output module outputs the transition layer and the original unstructured mesh as unstructured meshes for the unstructured solver to read and calculate, thereby obtaining the flow field information of the unstructured mesh; it also outputs the original structured mesh for the structured solver to read and calculate, thereby obtaining the flow field information of the structured mesh.
[0027] The structure solver is used to read and calculate the output structure mesh;
[0028] The unstructured solver is used to read and compute the output unstructured mesh.
[0029] The data exchange module exchanges the flow field information of the transition layer calculated by the structure solver with the flow field information of the transition layer calculated by the unstructure solver, based on the correspondence obtained by the corresponding module.
[0030] The transition layer selection module selects a transition layer that also includes the vertices where the unstructured mesh and the structured mesh intersect; the inner layer of the transition layer completely encloses the outer layer of the transition layer.
[0031] The inner and outer layers of the transition layer are separated by an interface, which is an offset surface at the junction between the structured mesh and the unstructured mesh.
[0032] The data exchange module, according to the correspondence, assigns the flow field information calculated by the structure solver of the transition layer to the unstructure solver, and assigns the flow field information calculated by the unstructure solver of the transition layer to the structure solver.
[0033] Thirdly, an electronic device is provided, comprising: at least one processor and a memory communicatively connected to the at least one processor, wherein the memory stores commands executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform any of the structured-unstructured hybrid data exchange methods described above.
[0034] This invention, based on previous structured / unstructured hybrid algorithms, addresses the issues of local discontinuities in the flow field when applied to complex 3D shapes and the low efficiency of finding transition layer units globally when the mesh size is large. By optimizing the data exchange method, the problem of local discontinuities in the flow field is solved, and the computational efficiency is improved.
[0035] In summary, this application includes at least the following beneficial technical effects:
[0036] (1) When selecting the transition layer, the vertices where the unstructured mesh and the structured mesh intersect are also included, which solves the problem of local discontinuity in the computational flow field;
[0037] (2) The transition layer elements in the structure solver are named during mesh generation, which reduces the time to find transition layer elements in the global scope when the mesh size is large, thus improving computational efficiency. Attached Figure Description
[0038] Figure 1 Schematic diagram of transition layer mesh optimization.
[0039] Figure 2 Schematic diagram of structured / unstructured hybrid grid data exchange.
[0040] Figure 3 Schematic diagram of grid division optimization for lateral jet interference in the shape of the grille wing.
[0041] Figure 4 Comparison of data exchange method before and after optimization of the flow field data exchange method for lateral jet interference of grid wing shape. Detailed Implementation
[0042] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0043] This application discloses a structured-unstructured hybrid data exchange method for jet interference problems, such as... Figure 1 , Figure 2 and Figure 3 As shown, it includes the following steps:
[0044] (1) For complex components, unstructured meshes are used to wrap and generate body-fitted meshes.
[0045] (2) Wrap the unstructured mesh area with two layers of structured mesh. When selecting the transition layer, wrap the vertices where the unstructured mesh and the structured mesh intersect. Then, partition and connect these two layers of structured mesh with the remaining structured mesh.
[0046] (3) Name the structured mesh blocks. Name the structured mesh layer closest to the unstructured mesh as the outer layer (block name prefix: interout), and the other layer as the inner layer (block name prefix: interin). For example... Figure 2 As shown.
[0047] (4) The unstructured mesh plus the two layers of structured mesh are used as the calculation area of the unstructured solver, and the structured mesh after docking is used as the calculation area of the structured solver.
[0048] (5) Based on the naming of the structural mesh block, find the transition layer mesh cell and obtain its center coordinates of the inner and outer layer mesh cells in the structural solver.
[0049] (6) Based on the condition that the center coordinates of the overlapping mesh cells are equal, find and mark the mesh cells in the unstructured solver according to the center coordinates of the inner and outer mesh cells of the transition layer cell in the structure solver.
[0050] (7) Based on the marked inner and outer mesh elements, assign the flow field information of the inner layer of the transition layer calculated by the structure solver to the unstructure solver, and assign the flow field information of the outer layer of the transition layer calculated by the unstructure solver to the structure solver.
[0051] (8) Update the flow field information of the structured subgrid and the unstructured subgrid.
[0052] (9) Completed.
[0053] This embodiment also discloses a structured-unstructured hybrid data exchange system for jet interference problems, including:
[0054] The mesh generation module uses an unstructured mesh to wrap the aircraft, generating a body-fitting unstructured mesh, and then uses a structured mesh to wrap the unstructured mesh.
[0055] The transition layer selection module, based on the interface between structured and unstructured meshes, extends a specified number of layers in the direction away from the unstructured mesh to form a transition layer. The transition layer also includes the vertices where the unstructured and structured meshes intersect. The transition layer is divided into two layers: the layer closer to the unstructured mesh is the outer layer, and the layer closer to the structured mesh is the inner layer. The inner layer completely encloses the outer layer. The interface between the inner and outer layers is the offset surface of the interface between the structured and unstructured meshes.
[0056] The naming module names the layer in the transition layer closest to the unstructured mesh as the outer layer of the transition layer, and the layer in the transition layer closest to the structured mesh as the inner layer of the transition layer.
[0057] The corresponding module obtains the center coordinates of the mesh cells in the structural solver based on the naming of the outer and inner layers of the transition layer; based on the condition that the center coordinates of the overlapping mesh cells are equal, it finds and marks the center coordinates of the mesh cells in the non-structural solver based on the center coordinates of the outer and inner layers of the transition layer in the structural solver, thus obtaining the correspondence.
[0058] The mesh output module outputs the transition layer and the original unstructured mesh as unstructured meshes for the unstructured solver to read and calculate, thereby obtaining the flow field information of the unstructured mesh; it also outputs the original structured mesh for the structured solver to read and calculate, thereby obtaining the flow field information of the structured mesh.
[0059] The structure solver is used to read and calculate the output structure mesh;
[0060] The unstructured solver is used to read and compute the output unstructured mesh.
[0061] The data exchange module, based on the corresponding relationship, assigns the flow field information calculated by the structure solver of the transition layer to the unstructure solver, and assigns the flow field information calculated by the unstructure solver of the transition layer to the structure solver.
[0062] This embodiment also discloses a structured-unstructured hybrid data exchange device for jet interference problems. The device includes: at least one processor and a memory communicatively connected to the at least one processor, wherein the memory stores commands that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the structured-unstructured hybrid data exchange method described above.
[0063] Example 1:
[0064] This invention conducts structured / unstructured hybrid mesh calculation tests on the flow field disturbed by the lateral jet flow of the grid airfoil shape, using an optimized data exchange method. The incoming Mach number is 4.5, the total incoming pressure is 1,491,000 Pa, the total incoming temperature is 306 K, the nozzle exit Mach number is 1, the total jet pressure is 3,877,000 Pa, and the total jet temperature is 306 K. Figure 1 Schematic diagrams before and after optimization of the transition layer selection are provided. Figure 4 The flow field diagrams of the lateral jet interference of the grid airfoil shape before and after the data exchange optimization method are presented. As can be seen from the figure, this method can solve the problem of local discontinuity in the calculated flow field of the previous structure / unstructured hybrid algorithm.
[0065] The contents not described in detail in this application specification are common knowledge to those skilled in the art.
[0066] The present application has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present application. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and implementation methods of the present application without departing from the spirit and scope of the present application, and all such modifications and improvements fall within the scope of the present application. The scope of protection of the present application is determined by the appended claims.
Claims
1. A structured-unstructured hybrid data exchange method, characterized in that, include: The unstructured mesh is used to wrap the aircraft to generate a body-fitting unstructured mesh, and then a structured mesh is used to wrap the unstructured mesh. Based on the interface between the structured and unstructured meshes, a specified number of layers are extended in the direction away from the unstructured mesh as a transition layer. The transition layer also includes the vertices where the unstructured mesh and the structured mesh intersect. The transition layer is divided into two layers: the layer closest to the unstructured mesh is the outer layer of the transition layer, and the layer closest to the structured mesh is the inner layer of the transition layer. The inner layer of the transition layer completely encloses the outer layer of the transition layer. The transition layer and the original unstructured mesh portion are output as unstructured meshes for the unstructured solver to read and calculate, thereby obtaining the flow field information of the unstructured mesh; the original structured mesh portion is output for the structured solver to read and calculate, thereby obtaining the flow field information of the structured mesh. The unstructured mesh and the structured mesh are mapped according to the transition layer; Based on the correspondence between the unstructured mesh and the structured mesh in the transition layer, the flow field information calculated by the structure solver in the transition layer is assigned to the unstructured solver, and the flow field information calculated by the unstructured solver in the transition layer is assigned to the structure solver. S7: Update the flow field information of the structured mesh and the unstructured mesh.
2. The structured-unstructured hybrid data exchange method according to claim 1, characterized in that: The transition layer, which is divided into two layers, is named as follows: the layer closer to the unstructured mesh in the transition layer is named the outer layer of the transition layer, and the layer closer to the structured mesh in the transition layer is named the inner layer of the transition layer.
3. The structured-unstructured hybrid data exchange method according to claim 2, characterized in that: The step of mapping unstructured meshes and structured meshes in the transition layer includes: Based on the names of the outer and inner layers of the transition layer, obtain the center coordinates of the mesh cells of the outer and inner layers of the transition layer in the structural solver; Based on the condition that the center coordinates of overlapping mesh cells are equal, the center coordinates of the mesh cells in the structure solver for the outer and inner layers of the transition layer are found and marked.
4. The structured-unstructured hybrid data exchange method according to claim 1, characterized in that: The specified number of layers is not less than 2.
5. The structured-unstructured hybrid data exchange method according to claim 1, characterized in that: The inner and outer layers of the transition layer are separated by an interface, which is an offset surface at the junction between the structured mesh and the unstructured mesh.
6. A structured-unstructured hybrid data exchange system for jet interference problems, characterized in that, include: The mesh generation module uses an unstructured mesh to wrap the aircraft, generating a body-fitting unstructured mesh, and then uses a structured mesh to wrap the unstructured mesh. The transition layer selection module extends a specified number of layers in the direction away from the unstructured mesh as a transition layer based on the interface between the structured and unstructured meshes. The transition layer is divided into two layers: the layer closer to the unstructured mesh is the outer layer of the transition layer, and the layer closer to the structured mesh is the inner layer of the transition layer. The naming module names the layer in the transition layer closest to the unstructured mesh as the outer layer of the transition layer, and the layer in the transition layer closest to the structured mesh as the inner layer of the transition layer. The corresponding module obtains the center coordinates of the mesh cells in the structural solver based on the naming of the outer and inner layers of the transition layer; based on the condition that the center coordinates of the overlapping mesh cells are equal, it finds and marks the center coordinates of the mesh cells in the non-structural solver based on the center coordinates of the outer and inner layers of the transition layer in the structural solver, thus obtaining the correspondence. The mesh output module outputs the transition layer and the original unstructured mesh as unstructured meshes for the unstructured solver to read and calculate, thereby obtaining the flow field information of the unstructured mesh; it also outputs the original structured mesh for the structured solver to read and calculate, thereby obtaining the flow field information of the structured mesh. The structure solver is used to read and calculate the output structure mesh; The unstructured solver is used to read and compute the output unstructured mesh. The data exchange module exchanges the flow field information of the transition layer calculated by the structure solver with the flow field information of the transition layer calculated by the unstructure solver, based on the correspondence obtained by the corresponding module.
7. A structured-unstructured hybrid data exchange system for jet interference problems according to claim 6, characterized in that: The transition layer selection module selects a transition layer that also includes the vertices where the unstructured mesh and the structured mesh intersect; the inner layer of the transition layer completely encloses the outer layer of the transition layer.
8. A structured-unstructured hybrid data exchange system for jet interference problems according to claim 7, characterized in that: The inner and outer layers of the transition layer are separated by an interface, which is an offset surface at the junction between the structured mesh and the unstructured mesh.
9. A structured-unstructured hybrid data exchange system for jet interference problems according to claim 6, characterized in that: The data exchange module, according to the correspondence, assigns the flow field information calculated by the structure solver of the transition layer to the unstructure solver, and assigns the flow field information calculated by the unstructure solver of the transition layer to the structure solver.
10. An electronic device, characterized in that, The electronic device includes: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores commands executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the structured-unstructured hybrid data exchange method according to any one of claims 1-5.