摘 要

赛车车身系统的气动性能对赛车特性有着至关重要的作用。本研究以武汉理工大学方程式赛车为研究对象，结合CFD分析和实车测试对赛车车身气动性能进行研究。首先运用仿生学原理进行赛车车身造型，并通过CFD分析及优化获得造型美观且阻力系数低的设计。通过升阻比分析确定最佳翼型，以翼片的攻角和相对位置为参数，进行正交试验分析及遗传算法优化，确定前鼻翼和后定风翼的最佳翼片设计。然后以扩散器的长度、角度和离地间隙为变量对扩散器进行参数化设计，通过仿真分析确定最优扩散器设计。最后将确定造型及安装位置的车身、前鼻翼、后定风翼及扩散器组合分析，确定各组件造型及安装布局对整车的气动性能特性的影响。

本文研究发现通过仿生学设计及车身局部优化可有效降低车身阻力系数，加装空气动力学套件能有效提高整车的负升力。赛车前鼻翼和后定风翼中翼片的攻角和相对位置是重要的设计参数，各参数对升阻比的影响程度不同，其中副翼片攻角和翼片间的横向距离对其影响较为显著。扩散器是各空气动力学套件中产生阻力最小而获得下压力最大的关键组件。各个组件的整体配合对提高整车空气动力学性能至关重要，在设计时应尽量使各套件间气流平顺过度。实车测试表明本研究获得的车身及各空气动力学套件优化设计方案能明显提高比赛成绩，并有效提升赛车驾驶稳定性。本文研究对FSC赛车车身系统的整体设计、分析及优化具有重要的指导意义。

关键词：FSC赛车；车身系统；气动性；分析；优化

Abstract

The aerodynamics of the racing car’s body system plays an important role in the performance of the car. Based on the FSC (formula student china) racing car of Wuhan University of Technology, we study the aerodynamic performance of the car body with the help of CFD. The main work of this study includes: the multiple sets of car body styling is created according to the principle of bionics design, and the optimal design of aesthetically pleasing and low drag coefficient is selected by CFD analysis. Then the airfoil is designed and optimized by CFD analysis. The angle of the wing and the distance between wings is studied by the orthogonal experiment. The multi-island genetic algorithm is applied to achieve the best wing design and the optimal installation position of the front wing and rear wing. For the diffuser, the length, angle and clearance to the ground is designed and optimized by CFD analysis. Finally, the car body, front wing, rear wing and diffuser are then analyzed in combination to determine the design and installation position.

According to this study, it is found that the drag coefficient is reduced effectively through the bionics design and local optimization of the car body. And the installation of the aerodynamic package can significantly increase the negative lift coefficient. The attack angle and relative position are important design parameters for the wing in the car. Their influence on lift-to-drag ratio is different, and the influence of the attack angle of the upper wing and the horizontal distance between the wings is significant. The diffuser is one of the most effective components in aerodynamics package, which produces greatest negative lift force with smallest drag force. The interaction of the components has great impact on the car’s aerodynamic performance, and the air-flow transition should keep fluent. In the field test, it is showed that the optimized solution achieved in this study can effectively improve the performance of the competition and the driving stability of the car. It is proved that this study is helpful for the design, analysis and optimization of the aerodynamic performance of FSC racing car.

Key words: FSC racing car; Car body system; Aerodynamic performance; Analysis; Optimizing

目 录

摘 要 I

Abstract II

目 录 I

第1章 绪论 1

1.1课题来源 1

1.2研究的背景及意义 1

1.3研究的现状 2

1.3.1汽车车身造型研究现状 2

1.3.2赛车气动性能研究现状 4

1.4本文研究内容 6

第2章 气动性研究理论基础 8

2.1气动性原理 8

2.1.1层流与湍流 8

2.1.2边界层理论 8

2.1.3文丘里效应及地面效应 8

2.1.4负升力产生理论 9

2.1.5翼型设计理论 10

2.2 CFD气动分析基础 11

2.2.1 CFD的概念 11

2.2.2控制方程和湍流模型 11

2.2.3离散化 12

2.3本章小结 13

第3章 FSC赛车车身系统设计 14

3.1 赛车车身设计 14

3.1.1仿生设计学的概念 14

3.1.2 赛车车身三维模型的建立 14

3.2赛车空气动力学套件设计 16

3.2.1 前鼻翼的设计 16

3.2.2 后定风翼的设计 16

3.2.3 底部扩散器的设计 20

3.3本章小结 21

第4章 FSC赛车车身系统气动性能分析及优化 22

4.1三维模型预处理 22

4.1.1赛车车身系统模型处理 22

4.1.2流体域的确定 22

4.2 网格生成 23

4.2.1 ANSYS ICEM CFD 23

4.2.2网格的划分 23

4.2.3赛车车身系统网格生成 23

4.3仿真计算 24

4.4仿真结果分析 25

4.4.1计算公式 25

4.4.2赛车车身气动性分析 25

4.4.3翼片气动性分析 26

4.4.4前鼻翼气动性分析结果 33

4.4.5后定风翼气动性分析结果 34

4.4.6格尼襟翼气动性影响分析 35

4.4.7扩散器气动性分析 36

4.5整车气动性分析 37

4.6 实车测试 40

4.6.1 FSC动态比赛项目 40

4.6.2 赛车跑道测试 41

4.7本章小结 42

第5章 总结与展望 44

5.1总结 44

5.2展望 44

参考文献 46

附录A 遗传算法实现程序 49

附录B 本科期间的学术活动及成果情况 52