| With the rapid development of domestic automobile industry in recent years,social problems such as energy crisis,environmental pollution become increasingly prominent,automotive energy conservation and emissions reduction is urgency.Car aerodynamics research give consideration both energy-saving and emission reduction,the wind resistance characteristic gradually become one of the important performance of the development of new vehicle project,OEMS are willing to invest a lot of manpower,money to do vehicle aerodynamic research and development through the CFD analysis and wind tunnel test.In this paper,based on CFD(Computational Fluid Dynamics)simulation analysis,detailed vehicle finite element model is established for aerodynamic research;Research model contains the cabin internal cooling system model;and the cooling system,to find out the cooling system influence to complete vehicle air drag.This paper focus on optimization analysis of vehicle grill air drag characteristics,except vehicle model building,the main content of the research is: the vehicle and grill air drag characteristics and optimization method for standard research,wind tunnel test verification,simulation benchmarking.This paper use CFD simulation as the main research methods,through the finite element modeling,analysis,optimization,to complete the simulation study of grill air drag characteristics,to get the exact air drag optimization solution and conclusion.Then,focus on research program to make theory application analysis via CFD simulation,to contrast Cd of optimization(Cd=0.3287)with baseline(Cd=0.3336).The Δ Cd(Cd contribution)is 4.5counts(1counts=0.001),confirm the effect of air drag.At the same time,utilize the CFD post-processing,compare and analyze the flow field,pressure and velocity contours change,confirm the optimization effect.After CFD theory application and optimization analysis,aerodynamic noise-vehicle wind tunnel test is conducted,to verify on “real” vehicle,to prove the accuracy of the theoretical research.Calculate the vehicle drag coefficient from simulation,and the optimized solution,air drag effect to carries on the corresponding real vehicle test,by comparing the air drag coefficient results between simulation and experimental,check the reliability of the simulation analysis and optimization solution,to record the differences between simulation and experimental resultsFinally,compare the error between simulation and experimental,study the reason of error,to realize the error lower than 1% between simulation and test,the correlation of simulation and test benchmarking,to make final confirmation for simulation accuracy,grill air drag characteristics optimization results. |
