Numerical Simulation And Model Optimization For Car Body

With the development of automotive technology and a growing scarcity of oil and energy, improve fuel economy and design a smaller aerodynamic drag car styling has become the subject of much attention. Aerodynamic characteristic is one of the important parameter that affect vehicle dynamic, economic performance and handing stability. And the car outflow characteristic reflects the aerodynamic characteristic well.Using computer aided design software Catia to complete modeling, using the software Hypermesh to complete meshing, using the powerful computational simulation and post-processing model simulation analysis abilities of computational fluid dynamics software Fluent to complete simulating. Then, carry out a research of a air outflow dynamic simulation of a passenger vehicle and styling optimization. The main work as follows:1. Comparing the wind tunnel test results of the clay mold of a SAIC commercial vehicle with its simulation results. To demonstrate the simulation results reliability of Fluent to provide evidence for the follow-up model simulations.2. Make a questionnaire survey for six automotive companies, to select six features,which have great impact on aerodynamic characteristics of the car, from 17 features.3. Change the parameters of the selected six features with 5% value, regard the drag coefficient as the optimization goal, through multiple simulation calculations, to select four greater impact features from that six features.4. Do an orthogonal experiment test for the selected four features based on the theory of orthogonal experiment. Select)3(49L orthogonal test form, from the viewpoint of multiple factors, regard the drag and lift coefficients as the goals, to obtain significant characteristic of four features, and according to it, the four features are given their best worthy, then get the best body shape.The optimization of automotive body styling will help to improve the car’s fueleconomy, power and handing stability. Using orthogonal test method can be more comprehensive, more accurate and time saving to optimize the car body shape. And this has great significance to the new product development and optimization for enterprises.