Visualization And Steering Computation Of Flow Field Based On Virtual Reality Technology

Most of the aerodynamic optimization design in modern aerospace industry is based on computational fluid dynamics(CFD)method.The process of aerodynamic optimization of using CFD is basically as follows: Flow field calculation and analysis of initial design,geometric model modification,re-divide mesh,flow field calculation of new model.For complex modelling,there is a heavy workload when optimizing with CFD,and the main task is grid regeneration after model modifying.In order to reduce the workload of aerodynamic optimization with CFD and enhance the interaction and controllability of the whole CFD process,a new aerodynamic optimization method based on virtual reality technology is explored,which integrates the whole process of CFD optimization into a platform.Then a method to modify the model and generate grid automatically in the platform is proposed to improve the efficiency of CFD optimization.Firstly,a desktop virtual reality system is constructed by virtual reality technology.Use the computer monitor as a window for user to interact with the virtual environment.Users can freely roam in the virtual environment using mouse and keyboard as interactive device.Meanwhile,the system provides a visualization method of flow field of streamline and contours,which is used for users to analyze the flow field.Secondly,the paper analyzes the data structure of the result of commercial software Fluent,which is commonly used in the current numerical solution of flow field.And compiles the related program to realize the data interaction between the results of fluent calculation and the virtual reality system.Then the CFD model and grid deformation method are designed and programmed.Based on the analysis of the flow field and its own experience,the user can use the interactive device to modify the initial model in the virtual environment.And the initial computational grid can deform automatically while the model is deformed.The transformed grid is automatically organized into Fluent data format,which can be directly re-calculation flow field.Using this method,the deformation operation of the geometric model can be completed in a platform,and the modified model is not required to be divided into grids,which improves the efficiency of the model optimization.Finally,use a two-dimensional nozzle model and a simple airliner model to demonstrate the operation flow and effect of the system designed in this paper.According to the analysis of the model,the deformation is performed,and the deformed model is calculated and the result is compared with the calculation results of the initial model.The result shows that the deformed mesh can be directly used for calculation,and the aerodynamic performance of the deformed model is improved.The result of the case demonstration shows the feasibility of the proposed method and the system designed in this paper.