Digital virtual fluid simulation method

Abstract

The invention relates to computational fluid mechanics visualization, in particular to a digital virtual fluid simulation method which is used for solving the problems that in the prior art, the space structure of a product cannot be effectively presented, and interactive data operation means are lacked. According to the method, an internal flow field or an external flow field and physical attributes of a simulation object are visually displayed by using a VR technology, and an internal structure of the simulation object is checked through interactive operation; during simulation, an empty root node is set for each simulation object, the interaction operation of the simulation objects is realized by transforming an interaction matrix of the root nodes, the interaction matrix is a matrix about a model, a view and projection, and the interaction operation comprises grabbing, scaling and editing of the simulation objects. According to the scheme, the ability of understanding and analyzing complex scientific data is greatly improved, and a brand new view angle and method are provided for scientific research.

Description

Technical Field

[0001] This case involves the visualization of computational fluid dynamics, and particularly relates to a digital virtual fluid simulation method. Background Art

[0002] Traditional medical image visualization does not have fluid data, and only slices through scan results such as CT and views them on a two-dimensional screen. Users cannot perceive the entity and cannot intuitively combine it with physical structures (wall shear stress, flow rate, electrical potential signal). Even when using fluid dynamics simulation, the combination and rendering of simulation results in immersive devices lack interaction methods when presented to users. Summary of the Invention

[0003] To at least solve some of the problems existing in the prior art, this case proposes a digital virtual fluid simulation method and system, which combines scientific fluid simulation with virtual reality to jointly help users perceive the entity and also combine it with physical properties (wall shear stress, flow rate, electrical potential signal), enabling users to have a more intuitive and detailed immersive experience and enhancing users' understanding and exploration ability of simulation results. The specific solutions are as follows.

[0004] In a first aspect, this case proposes a digital virtual fluid simulation method. The method uses VR technology to visually display the internal flow field or external flow field and physical properties of a simulation object, and views the internal structure of the simulation object through interactive operations. During simulation, an empty root node is set for each simulation object, and the interactive operations on the simulation object are achieved by transforming the interaction matrix of the root node. The interaction matrix is a matrix regarding the model, view, and projection, and the interactive operations include grasping, scaling, and editing of the simulation object.

[0005] In an implementation of the above technical solution, the editing includes cropping, and the steps include: obtaining a cutting plane, moving the plane, performing real-time transparency calculation on the retained part, and using Alpha cropping in the fragment shader stage to retain the visible part of the object; or directly performing vertex culling based on the positions of the object vertices to form triangular meshes and form a toothed cross-section;

[0006] In an implementation of the above technical solution, the editing includes sculpting, and the sculpting is achieved by recalculating the internal flow field through computational fluid dynamics and fitting it with the expected target.

[0007] In an implementation of the above technical solution, the sculpting is achieved by using a brush to modify the vertices on the surface of the simulation object and realizing expansion or excavation according to the position of the spherical brush relative to the surface.

[0008] In one implementation of the above technical solution, the carving further includes an operation of adsorbing the surface vertices to the spherical crown area of the spherical brush.

[0009] In one implementation of the above technical solution, when setting the inlet boundary condition of the internal flow field or the external flow field of the simulation object, calculate the velocity target value of all points on the inlet section to reduce the boundary diminishing effect.

[0010] In one implementation of the above technical solution, the internal flow field or the external flow field of the simulation object is displayed by dynamic streamlines. When the streamlines are drawn, different-sized anchor balls are placed as the regions of interest, and the random point clouds inside the anchor balls are used to generate the streamlines flowing through this region, or a line is placed to generate a group of streamlines flowing through this line.

[0011] In one implementation of the above technical solution, the streamlines are colored according to the velocity.

[0012] In one implementation of the above technical solution, the visualization display is achieved by color-coding the partition information of the simulation object through the geometric region decomposition method in parallel computing technology.

[0013] In a second aspect, this case proposes a computer-readable storage medium storing a computer program that can be loaded and executed by a processor to perform any of the above methods.

[0014] The beneficial technical effects of this case: Through the digital virtual fluid simulation method proposed in this case, scientific visualization can be achieved, and the latest achievements of high-performance computing in multiple fields such as medical simulation and construction engineering can be presented to users, enabling popular science education and cutting-edge research analysis. In medicine, it can be used to implement virtual surgery, enabling intuitive visualization of the internal structure of organs, analyzing wall shear stress and blood flow velocity, and achieving the purpose of treating patients. In construction engineering, it can achieve model optimization, providing a realistic experience of the wind field between cities, and thus enabling the use of wind force intensity and eddy current position data for optimizing or improving the design. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 、 one Schematic diagram of structural integration in a certain implementation.

[0017] Figure 2 、 oneSchematic diagrams of serrated cutting and smooth cutting in a certain implementation manner.

[0018] Figure 3 、 one Schematic diagrams of surface expansion, extrusion and adsorption in a certain implementation manner.

[0019] Figure 4 、 one Schematic diagram of setting the inlet boundary velocity condition in a certain implementation manner.

[0020] Figure 5 、 one Schematic diagrams of the mutual conversion and visualization of surface, point cloud and volume data in a certain implementation manner.

[0021] Figure 6 、 one Schematic diagrams of grasping, scaling and cutting in a certain implementation manner.

[0022] Figure 7 、 one Schematic diagram of editing the model surface to achieve the purpose of virtual surgery in a certain implementation manner.

[0023] Figure 8 、 one Schematic diagrams of a dynamic heart model and internal display of multiple physical fields in a certain implementation manner.

[0024] Figure 9 、 one Schematic diagrams of generating streamlines by sprinkling points inside using multiple methods in a certain implementation manner.

[0025] Figure 10 、 one Schematic diagram of visual adjustment of the internal process in a certain implementation manner.

[0026] Figure 11 、 one Schematic diagram of heart aorta simulation in a certain implementation manner.

[0027] Figure 12 、 one Schematic diagram of wind field simulation of nuclear power plant buildings in a certain implementation manner.

[0028] Figure 13 、 one Schematic diagram of wind field simulation of buildings in the city center in a certain implementation manner. Specific implementation manners

[0029] Immersive experiences have proven to have significant practical effects in many visualization application scenarios, including medical imaging, scenic real scenes, and product displays. With the help of immersive devices and virtual reality (VR) technology, users can observe anatomical structures such as the heart and brainstem three-dimensionally, and deeply explore the complex relationships between structures and pathologies, thus endowing profound significance to medical education. In the field of urban planning, researchers can perceive the real environment through virtual scenes. Without on-site inspections, they can use scaled-down models and full-scale scenes at the initial stage of planning to identify design flaws and optimize construction plans. In addition, in terms of product appearance display, immersive technology can provide purchasers with a comprehensive and accurate viewing experience. Even if the physical object cannot be displayed, it can effectively present the product structure.

[0030] However, although the simple three-dimensional model display and interaction in immersive experiences embody the user-centered design concept, can comprehensively convey real-world information, and help users better understand and explore the underlying laws, it is equally crucial for users in professional fields to obtain more abstract and unrealistic complex information. Scientific visualization aims to be designed around human perception with physical information as the basic attribute to meet the needs of professionals for physical property information. We focus on the field of fluid simulation and help professionals with education and analysis by visualizing relevant information. For example, doctors can diagnose causes such as myocardial ischemia and blood reflux by analyzing data such as wall shear stress, blood flow velocity, and flow rate; architectural designers can use data on wind intensity and vortex position for optimization design, thereby extending the building's lifespan, improving the comfort of the pedestrian wind environment, and enhancing pollutant emission effects. For products such as ventilation systems and heat dissipation devices, analyzing the relationship between fluid media and transmission power can effectively reduce energy consumption, improve emission efficiency, and enhance product performance.

[0031] Based on this, this case proposes a framework for scientific visualization in virtual reality, especially computational fluid dynamics (CFD), to implement an immersive physics simulation-based platform for displaying the latest achievements of computational fluid dynamics, reveal more intuitive laws of computational fluid dynamics through visualization, and be able to interactively present the combination and rendering of fluid dynamics simulation results in immersive devices to users, realizing guidance from education to practical applications. Through the method or system of this case, it is possible to jointly reveal computational results from aspects such as viewing and modifying geometric structures, dynamically displaying multiple physical fields, and Lagrangian expressions inside the flow field, bringing a refreshing immersive experience to the general audience, and also bringing unprecedented cognition and inspiration to relevant medical workers and urban planners.

[0032] The following will clearly and completely describe how to implement the technical solution of this case in conjunction with the accompanying drawings. Obviously, the described implementation manners are only a part of the implementation manners of this case, rather than all of them. Based on the implementation manners in this case, all other implementation manners obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by this application.

[0033] Developing visualization software using modern game engines has become a common practice. In Unity, a GameObject is a combination of an object and its behaviors and is divided into a whole according to the physical or logical hierarchy and can be saved as prefabs. This enables the application to different scenarios, or even different environments (VR, MR, AR) by configuring prefabs for multiple cases. In this case, the latest Unity6 is used, which includes more GPU optimizations and the latest packages to ensure that our design concept always remains at the forefront.

[0034] Currently, XR development is not yet mature, and various hardware devices, such as diverse handle controllers, eye trackers, body movement trackers, visual gestures, and even treadmills, pose great challenges to the unity of input. In addition, there are endless interaction methods, and past common interaction concepts, such as direct ray interaction and pinch-to-zoom, have gradually been deprecated. This case adopts the latest XRI interaction system, which solves various interaction problems through the binding of button actions and closely follows the latest interaction designs to strive for long-term support for the interaction framework. The hardware used in this case is the HTC Vive Pro 2 with 8K resolution, bringing users a delicate and shocking immersive visual experience, especially in the dynamic streamline part. However, this also poses higher requirements for program optimization. In short, this case adopts the most advanced VR technology currently, combines high-performance numerical simulation and emulation, and jointly creates a scientific computing virtual digital laboratory with high-quality content through the display of multiple cases.

[0035] In the immersive model interaction of scientific visualization, changes in the interactive spatial position and the affordances of various interactions need to consider component-based design, just like most projects in Unity. This object-oriented combined design pattern facilitates diverse operations on individual objects and ensures the unity of the positions of internal objects (such as internally generated streamlines) and the surface mesh.

[0036] As Figure 1As shown, an empty object is set as the root node. Under the empty root node, there are sub-nodes such as surface, attachments, and visual settings. For each simulation object, a hierarchical structure is set based on the empty root node. When moving a simulation object, what is moved is the whole of all the internal geometries contained in the simulation object, which is different from the VR interaction method in ParaView: in ParaView, all internal objects are split, and cases are scattered when moving different components. In addition to the interaction level, setting the hierarchical structure can also achieve operations such as overall transformation.

[0037] In terms of performance optimization, setting the parent object can effectively utilize the MVP (Model, View, Projection) matrix for optimization. For child objects, it can avoid modifying their positions and sizes relative to the parent object, so that the MVP matrix of the child object is the same as that of the root object. Integrating the interaction matrix into one, which contains information such as position movement, rotation quaternion, and scaling factor, then calculating the influence of each child object is an operation after the inverse transformation of the MVP matrix. In this way, by setting an empty root node for the simulation object and only transforming the interaction matrix of this root node, the number of spatial conversions at the interaction points is reduced, the position consistency of multiple components and various interactions is seamlessly achieved, and the user's spatial perception of the entire model is efficiently enhanced. The aforementioned parent object is the entire simulation object, and the child object is a component of the simulation object.

[0038] Model editing (preprocessing):

[0039] In this case, a clipping technology is designed and developed to check the internal structure of the model and a sculpting tool for virtual surgery. These functions include the basic operations of viewing and editing the model, and support an intuitive interaction method centered on the user. Since immersive interaction and visual experience have the ability of precise three-dimensional spatial perception, they have long been considered helpful for surface rendering and editing. In our virtual laboratory, we perform visual clipping (without modifying the mesh data) to deeply view the physical information of the inner and outer walls of the organ and observe the representation of the internal velocity field. In the virtual environment, the sculpting function can expand or contract a narrow tumor, recalculate the internal flow field through computational fluid dynamics, obtain parameters such as flow rate and pressure, and fit them with the expected target, so as to achieve the purpose of shape planning, which can be applied to virtual surgery.

[0040] Clipping and internal visualization:

[0041] In scientific visualization, it is often necessary to view the internal information of an object. For performance considerations, we implemented a simplified clipping operation on the GPU. Through a small component, we can obtain a cutting plane. Moving this plane, the part of the model in front of the plane is removed, while the part behind is retained. We perform real-time transparency calculations on the GPU and use Alpha clipping in the fragment shader stage to retain the visible parts of the object. It should be noted that our calculations are performed at the fragment level, enabling Alpha assignment pixel by pixel, thus achieving a smooth clipping effect, as shown in the right figure of Figure 2 as shown. Conversely, we also implemented another type of crinkle clip, as shown in the left figure of Figure 2 . Vertex culling is directly performed based on the positions of the object vertices, resulting in residual triangular patches and a jagged cross-section. Although this method lacks aesthetic appeal, it is very effective for internal viewing and statistics of mesh generation in professional fields such as computational fluid dynamics (CFD).

[0042] During the sculpting process, the brush is a crucial factor. We use a scalable small sphere as the brush to modify the vertices on the model surface. For example, as shown in the left and middle figures of Figure 3 , selecting an appropriate brush size can achieve expansion or digging operations on the model, and the specific effect depends on the position of the brush relative to the surface: when the brush is outside the surface, a "push" operation can be achieved; when the brush is inside the surface, a "pull" operation can be achieved.

[0043] In addition, we designed a new technique different from traditional sculpting methods, as shown in the right figure of Figure 3 (the dashed line in the figure is the brush, a spherical cap). The main difference from the previous method is that this method achieves the sculpting operation by attracting the surface vertices to the local area inside the spherical brush (i.e., the spherical cap area, Spherical Cap). In this method, the sculpting process requires pushing the vertices out of the spherical brush, and the snap operation is achieved by changing the constraints of vertex movement: that is, when the vertex distance from the brush sphere exceeds a certain threshold, the external vertices will be attracted to the brush sphere surface. This improvement provides a more flexible and diverse operation method for sculpting, further expanding the application potential of sculpting technology.

[0044] Simulation based on hydrodynamics:

[0045] Regarding simulation methods, a large number of related studies have been deeply explored. The visualization of various hydrodynamic calculation results is demonstrated through the following types of cases, thus comprehensively presenting the diversity and applicability of high-performance numerical calculations. Specifically, these cases include the following types:

[0046] First, we presented the computational results based on the finite element method (FEM), including cerebrovascular models and cardiac aorta models. These examples highlighted the high-precision advantages of the finite element method in complex biomechanical problems.

[0047] Secondly, we introduced two urban cases calculated using the finite volume method (FVM). These cases simulated the fluid behavior in the urban environment, demonstrating the wide application of the finite volume method in engineering and environmental problems.

[0048] Finally, we combined machine learning techniques and presented two examples of accelerated fluid calculations for flow field simulations in narrow and tumor regions respectively, indicating the potential of machine learning methods in complex fluid calculations.

[0049] For different calculation methods, we need to adjust their boundary conditions (such as inlet velocity, pressure distribution, etc.) according to specific problems. For example, in the machine learning method, the flow field is calculated using a point cloud structure, which can flexibly handle irregular geometries. When setting the inlet boundary condition, in order to consider the boundary decay effect, we calculated the velocity target values of all points on the inlet section, as Figure 4 shown. These target values not only reflect the spatial variation characteristics of the boundary conditions but also lay the foundation for accurately simulating fluid behavior.

[0050] Through these cases, we not only verified the applicability of various simulation methods in different scenarios but also demonstrated the wide application potential of high-performance computing technology in complex fluid mechanics problems.

[0051] Case study:

[0052] Based on the characteristics and requirements of different cases, various interactive tools can be designed to enable users to flexibly operate each model. These interactive tools are invoked through virtual menus and provide diverse functional supports to facilitate users to complete complex interactive behaviors. For example, as Figure 6 shown, each model is bound to interactive behaviors implemented through its root node. Users can use the controller to perform operations such as grasping, scaling, and cutting on the model. In the figure, a is an example of blood vessels in the stenotic region of the cardiac artery. In figure b, the model is grasped in the hand and rotated and scaled following the hand for basic operations. Figure c shows the cutting operation, where one can observe the inner wall in depth. Figure d represents the repositioning of the model.

[0053] In addition, to facilitate the observation of the internal structure of an object, we also designed a cropping tool. When the user activates the cropping tool, a cropping plane can be generated to cut the model open to expose its internal details, further enhancing the depth of model interaction and exploration. Through this intuitive interaction method, users can understand and manipulate virtual objects in a more natural and efficient way, thus enabling more in-depth research or teaching applications.

[0054] For typical problems in medical research, two cases were designed. The model was modified through virtual surgery to provide targeted guidance and research support. For example, Figure 7 in c of Figure 7 and d of Figure 7 in a of Figure 7 and b of

[0055] In these two cases, we used the sphere brush tool in the virtual reality environment to interactively modify the model, as shown in the figure. For the coronary artery stenosis area, we can use the brush tool to dilate the restricted part to simulate the effect of surgical intervention; while for the tumor area, we can use the same tool to reduce the tumor volume to evaluate the improvement effect of different surgical methods on blood flow.

[0056] Comprehensive and Immersive Problem Discovery and Diagnosis of Digital Twin Heart

[0057] In our heart simulation case, by combining the beating animation with the visualization of multiple physical fields (such as velocity field, electric field, and displacement deformation information), the dynamic behavior of the heart and its internal driving mechanism can be comprehensively presented. Through the clip operation (cropping operation), users can deeply view the internal structure of the model, thereby conducting more in-depth research on the heart beating pattern and the myocardial contraction and relaxation driven by bioelectric signals.

[0058] In addition, we used the geometric domain decomposition method in parallel computing technology to visualize the partition information of the heart model through color coding. In this way, not only can we observe the load balance of the partitions on the supercomputer, but also verify the uniformity of the domain division to ensure that there are no long and narrow or irregular overlapping areas, which is crucial for the efficiency and convergence of parallel algorithms.

[0059] Figure 8 In a, the deformation intensity of different parts of the heart is shown. It can be seen that the deformation at the inlet and outlet is small, presenting a relatively fixed state, while the deformation in the atrium and ventricle parts is relatively intense due to the expansion and contraction of cardiomyocytes. Figure 8 In b, the parallel region decomposition of the geometry is shown. The size of each region is approximately equal, achieving load balancing, and at the same time revealing the distribution characteristics of the overlapping regions, further proving the optimization effect of the algorithm.

[0060] After the cropping operation, we can keep the segmented model in the current state and perform grasping and scaling, as Figure 8 shown in c, providing flexible interaction capabilities for observing details. Finally, Figure 8 In d, the lag relationship between different parts during the heart beating is shown. The electric potential is transmitted from the orange area to the blue area, driving the contraction of cardiomyocytes at the same time, and as the electric potential decreases, the myocardium gradually relaxes.

[0061] The differences between the two processes can be intuitively felt from the immersive device: the electric potential signal is transmitted rapidly, resulting in clear boundary changes; while the relaxation process is relatively slow, corresponding to the gradually weakening deformation in the animation. This visualization clearly reveals the driving law of the electrocardiogram signal on the heart beating, providing valuable tool support for the study of cardiac biomechanics and electrophysiology.

[0062] Visualization and analysis inside the flow field

[0063] Visualization of the velocity field is a difficult point. We use dynamic streamlines to display the internal flow field. For the drawing of streamlines, first, appropriate seed points are selected. We provide two methods to interactively select seed points: one is the random point cloud inside the anchored sphere, and the other is the equally spaced sampling points on the line segment. The number of seed points placed can be determined by density adjustment. As Figure 9 shown in a and b, we can place a line and then generate a group of streamlines flowing through this line. As Figure 9 shown in c and d, we can place anchored small balls of different sizes as the regions of interest and randomly generate streamlines flowing through this region.

[0064] At the same time, the adjustment of color and dynamic effects is also very helpful for the internal visualization of the flow field. For example, color gradients and transparency can significantly improve the visualization of the regions of interest. Our streamlines are also colored with the physical quantity of velocity. In the low-speed area, such as Figure 10 the lines are in the red area and tend to form vortices. By adjusting the transparency and color, a more obvious contrast can be presented, making it more obvious and convenient for researchers to study.

[0065] In summary, by presenting multiple cases, we have demonstrated the latest achievements of high-performance computing in various fields such as medical simulation, education and training, and architectural engineering. This framework also represents the cutting-edge progress of scientific visualization achieved through modern graphics technology and extended reality (XR) interaction. In our virtual environment, it not only includes examples of the stenotic region of the heart aorta and cerebral vascular tumors (see Figure 11 ), where users can zoom in and enter the blood vessels for observation, which helps for meticulous examination; but also includes a model of the urban wind field. Through immersive interaction with equal-scale magnification, users can feel the urban wind field as if they were on the spot (see Figure 12 , Figure 13 ), which is of great significance for urban planning and wind environment research. In these cases, we have also adopted a fluid calculation method based on machine learning. In the post-processing visualization layer, by magnifying the model, users can clearly understand physical information such as wall shear stress (WSS). And in the pre-processing, with the help of the Clip and MeshEditor, simple editing of objects can be performed to achieve virtual surgery or model optimization, aiming to treat patients or improve the design.

[0066] Compared with the prior art, this case introduces a high-precision interaction design based on a modern graphics engine. For example, by using dynamic streamlines, shear planes, and sculpting tools, users can operate and observe the flow field and physical properties inside the model in real time. Especially for the in-depth viewing of the internal structure of complex geometric models (such as blood vessels and wind fields), it realizes a more intuitive and meticulous immersive experience, which significantly improves the understanding and exploration ability of researchers on the simulation results. This case not only supports the visualization of traditional hydrodynamic parameters (such as wall shear stress and flow velocity), but also combines the dynamic display of multi-physical field information such as electric fields and deformations. Especially in cardiac simulation, through the linked visualization of the transmission of electrophysiological signals and the dynamic deformation of the myocardium, it provides a more comprehensive data analysis platform for medical research and teaching. The prior art is usually limited to static visualization, while this case realizes the dynamic editing of the model surface (such as dilation, contraction, etc.) by introducing a brush tool, and can recompute the results in combination with fluid simulation. This function greatly expands the application scope of virtual surgery and design optimization. This case not only presents a single fluid simulation case, but also constructs a complete digital twin fluid dynamics laboratory, supporting full-process functions from geometric processing to multi-physical field visualization to interactive editing. Compared with the scattered functional modules of the prior art, the present invention provides a complete and integrated platform for users.

[0067] Through the description of the above embodiments, those skilled in the art can clearly understand that a corresponding system can be implemented according to the method of the present disclosure.

[0068] Through the description of the above embodiments, those skilled in the art can clearly understand that the method or system of the present disclosure can be implemented by means of software plus necessary general hardware. Of course, it can also be implemented by dedicated hardware including application-specific integrated circuits, dedicated CPUs, dedicated memories, dedicated components, etc. Generally, functions accomplished by computer programs can be easily implemented by corresponding hardware, and there can be various specific hardware structures for implementing the same function, such as analog circuits, digital circuits or dedicated circuits, etc. However, in more cases for the present disclosure, implementation by software programs is a better embodiment.

[0069] Although the embodiments of this case have been described above in conjunction with the accompanying drawings, this solution is not limited to the above specific embodiments and application fields. The above specific embodiments are merely illustrative and guiding, rather than restrictive. Those of ordinary skill in the art can also make many forms under the inspiration of this specification and without departing from the scope protected by the claims of this case, and these all fall within the scope of protection of this case.

Claims

1. A digital virtual fluid simulation method, characterized in that: The method uses VR technology to visualize the internal flow field or external flow field and physical properties of the simulated object, and views the internal structure of the simulated object through interactive operations; During simulation, a root node including an empty node is set for each simulation object. The interactive operation of the simulation object is realized by transforming the interactive matrix of the root node. The interactive matrix is ​​a matrix about the model, view and projection. The interactive operation includes grabbing, scaling and editing the simulation object.

2. The method according to claim 1, characterized in that The editing includes cutting, and the steps include: Get a cutting plane, move the plane, perform real-time transparency calculation on the retained part, and use Alpha clipping in the fragment shading stage to retain the visible part of the object; or directly cull vertices according to the position of the object's vertices to form triangular facets and tooth-shaped cross-sections.

3. The method according to claim 1, characterized in that The editing includes carving, and the carving is achieved by recalculating the internal flow field through computational fluid dynamics and fitting it with the expected target.

4. The method according to claim 3, characterized in that The carving modifies the vertices of the surface of the simulation object by using a sphere brush, and realizes expansion or excavation according to the position of the sphere brush relative to the surface.

5. The method according to claim 3, characterized in that: The sculpting also includes snapping surface vertices to the cap area of ​​the sphere brush.

6. The method according to claim 1, characterized in that When setting the inlet boundary conditions of the internal flow field or external flow field of the simulation object, the velocity target values ​​of all points on the inlet section are calculated to reduce the boundary diminishing effect.

7. The method according to claim 1, characterized in that The internal or external flow field of the simulated object is displayed through dynamic streamlines. When drawing the streamlines, anchor balls of different sizes are placed as the area of ​​interest, and the random point clouds within the anchor balls are used to generate streamlines flowing through the area, or a line is placed to generate a group of streamlines flowing through the line.

8. The method according to claim 6, characterized in that Streamlines are colored according to their speed.

9. The method according to claim 1, characterized in that: The visual display is achieved by color coding the partition information of the simulation object using a geometric region decomposition method in parallel computing technology.

10. A computer-readable storage medium, characterized in that: A computer program is stored which can be loaded by a processor and execute the method according to any one of claims 1 to 9.

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