论文总字数：19272字

摘 要

进气系统对整个汽油机的各个性能都有很大的影响，是汽油机五大系统中供给系的重要组成部分。研究汽油机进气系统具有重要的意义，因为它对油气混合、滞燃期、着火、燃烧等都有着非常重要的影响。

首先是进排气系统对汽油机性能的影响的介绍，包括简要介绍进排气系统的组成、功能以及整体。进排气管的直径和长度对汽油机的速度特性的影响是针对进排气系统对汽油机性能影响的参数中选择影响较为显著的两个因素。

本文要依据汽油机的一些参数，来检验这种模型是否正确。使用软件AVL-BOOST来构建出一个物理模型。将所得的发动机的三个性能指标数据，功率、比油耗、转矩进行汇总，整理成散点图。将计算出来的结果进行比较，来探索发动机的各方面性能受进排气管变化的一些影响。

另外，以3mm为一个单位进行变化对该汽油机模型进行仿真模拟计算，在不同转速下改变进排气管直径，进行分析，从而知道进排气管的直径大小对发动机的一些性能的影响有多大。经过比较计算，选择出最好的方案。

经过精确分析计算结果后最后我们发现，增大进气管的直径和长度，想要提高发动机的高速段转矩和最大转矩可以大进气管的直径和长度；但我们发现汽油机的燃油消耗率提高了许多，同时发动机的高速段转矩会随着进气管长度直径的增加产生较大的损失。所以要使燃油消耗不要太高而影响汽油机的经济性能并且汽油机的转速和功率得到很大的提高，只能选择中速择优的方案。

关键词：发动机性能 进排气系统

Abstract

An important part of the supply of gasoline engine intake system five system, have a great impact on the flow of gas intake system of the engine power, economy and emission characteristics. It is the mixture of oil and gas, the ignition delay period, ignition, combustion, flame spread, heat emission, and the gasoline engine knock and cyclic variations have important influence, so it is important to study the petrol engine intake system.

Firstly, through the brief introduction of intake and exhaust system composition, function and overall introduced the effects of intake and exhaust system on gasoline engine performance. Selection of parameters in view of the influence of intake and exhaust system on performance of gasoline engine in two factors significantly influence the speed characteristics, into the exhaust pipe diameter and length of the gasoline engine.

According to the main parameters of gasoline engine, the use of physical model is established with AVL-BOOST software, verification and simulation, verifies the correctness of the model. According to the model of the gasoline engine in different speed will into the exhaust pipe length changes in 20mm as a unit, followed by simulation calculation, the engine torque, power, specific fuel consumption of three performance data will be collected, collated into a scatter diagram. Comparing the results, research into the exhaust pipe, length change influence on engine performance; in addition, change into the exhaust pipe diameter under different rotational speed, using 3mm as a unit change simulation calculation on the model of the gasoline engine, draw the dispersion analysis diagram of calculation results, the effects of inlet and exhaust pipe diameter on the engine performance. Through the calculation and comparison, select the optimal scheme.

Finally, the results found, increase the intake pipe length and diameter, can improve the speed of engine torque and maximum torque; but with increasing length of inlet pipe diameter, will make the high torque engines produce more losses, while gasoline engine fuel consumption rate improved a lot. So only choose medium preferred plan, not only make the engine speed and power has been greatly improved, but not so that the fuel consumption rate is too high, thus affecting the economic performance of the engine.

Keywords: Engine performance; The intake and exhaust system.

目 录

第一章 绪论 1

1.1 引言 1

1.2 进排气系统 1

1.2.1进排气系统简介 1

1.2.2进排气系统的组成 4

1.2.3进排气系统的分类 4

1.2.4进排气系统的功用及对汽油机的影响 5

1.3进排气系统研究现状 5

1.4本论文主要研究内容 7

第二章 建立BOOST模型与验证 8

2.1BOOST软件简介 8

2.2 BOOST模型建立过程 11

2.2.1 汽油机参数 11

2.2.2 BOOST模型建立 11

第三章 分析进排气系统对汽油机性能的影响 13

3.1进排气管长度对汽油机性能的影响 15

3.1.1进气管长度对汽油机的性能影响 17

3.1.2排气管长度对汽油机的性能影响 19

3.2研究进排气管直径对汽油机性能的影响 22

3.2.1进气管直径对汽油机性能的影响 22

3.2.2排气管直径对汽油机性能的影响 24

3.3 计算结果优化分析 26

第四章 总结与展望 27

4.1总结 27

4.2展望 27

参考文献...................................................................................................................30

致谢..........................................................................................................32

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