摘 要
随着计算机技术的不断发展，发展到现在包括了扰流板、发动机舱、车轮等更为复杂的车体模拟，同时还对横风稳定性和横风过渡特性、两车相遇时的瞬态空气动力学特性等进行研究。在精度方面，可以把计算精度误差降到5%以内。目前国外对汽车外流场的湍流解析模型主要是k-ɯ模型、应力方程模型为代表的模型和空间平均的大涡模拟法(LES)。国外在计算流体力学的结果分析中大量采用了可视化技术。可视化技术可以凭借计算机把数字信息转化为易于研究人员分析和理解的图形或动画，加快对模拟对象的认识，提高工作效率。由于计算机的普及及价格优势，使其成为研究人员进行数值模拟和分析的主要工作平台。目前，数值模拟最主要的问题就是计算精度问题。
运用Fluent流体分析软件对车辆进气系统特性进行三维数值模拟分析，进气消声系统内部流动特性进行三维数值模拟分析，根据仿真分析的结果得出气流速度、温度和压力分布规律，从而确定进气系统的改进方向。本课题将涉及到热力学、声学、流体力学等多门学科，具有一定的学术价值和工程应用价值。应用Fluent流体力学分析软件建立进气系统内部数值计算模型，模拟结果可以用于指导实验研究，节约实验次数和时间，促进进气系统结构改进。根据《汽车电子控制技术》课程学习的知识，系统分析发动机进气系统设计及性能同时结构组成及基本的工作原理，掌握汽车电子控制系统的基本结构与原理。
关键词：进气系统；消声元件；空气滤清器；流场仿真
ABSTRACT
With the continuous development of computer technology，the development now includes more complicated simulation of car body such as spoiler，engine cabin，wheel and so on，at the same time，it is also applied to the stability of cross-wind and the characteristics of cross-wind transition. The transient aerodynamic characteristics of the two vehicles when they meet are studied. In terms of accuracy，the accuracy error can be reduced to less than 5%. At present，the turbulence analytical model of automobile external flow field abroad is mainly k-k model，the stress equation model is represented by the model，and the spatial average large eddy simulation method (LES).) is used. Visualization techniques are widely used in the analysis of computational fluid dynamics (CFD) results abroad. Visualization technology can rely on the computer to put the number The information can be transformed into graphics or animations which are easy to be analyzed and understood by researchers to accelerate the understanding of simulated objects and improve the efficiency of work. Because of the popularity and price advantage of computer，it has become the main working platform for researchers to carry out numerical simulation and analysis. At present，the most important problem of numerical simulation is the calculation accuracy.
The three-dimensional numerical simulation and analysis of the characteristics of the intake system and the internal flow characteristics of the intake system are carried out by using the Fluent fluid analysis software，and the velocity of the air flow is obtained according to the results of the simulation analysis. The distribution law of temperature and pressure，so as to determine the direction of improvement of the intake system. This subject will involve many subjects such as thermodynamics，acoustics，fluid mechanics and so on. It has certain academic value and engineering application value. The numerical calculation model of intake system is established by using Fluent hydrodynamic analysis software. The simulation results can be used to guide the experimental research，save the number and time of experiment，and promote the intake system. The system structure is improved. According to the knowledge of the course "Automotive Electronic Control Technology"，this paper analyzes systematically the design and performance of the engine intake system and its structure and basic working principle，and master the basic structure and principle of the automotive electronic control system.
Key words：intake system；muffler；air filter；flow field simulation
目 录
摘 要 I
ABSTRACT II
第1章 绪论 1
1.1研究背景 1
1.2研究现状 2
1.2.1国外的研究概况 2
1.2.2国内的研究概况 3
1.3研究思路及方法 4
第2章 车辆进气系统流场消声元件设计 6
2.1进气系统概述 6
2.1.1进气系统结构及工作原理 6
2.1.2进气噪声的产生机理 7
2.2进气消声元件优化 8
第3章 车辆进气系统流场仿真分析 10
3.1进气歧管流场分析模型的建立 10
3.1.1计算流体力学基本理论 10
3.1.2进气歧管流场分析方法 11
3.2汽车加速行驶车外噪声分析 12
3.2.1理论介绍 12
3.2.2模型的建立 13
3.2.3结果分析 13
第4章 总结与展望 15
4.1全文总结 15
4.2展望 16
参考文献 17
致 谢 18
