六缸柴油机排气消声器的设计及仿真研究

发布时间：2018-01-27 05:23

本文关键词： 消声器噪声仿真模拟 GT-POWER　出处：《大连理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着汽车行业和交通运输业的快速发展,人们对汽车的依赖性越来越强,也因此我国汽车保有量逐年大幅度的增加,当前城市的汽车噪声治理面临着更大的压力与挑战,同时人们对汽车的舒适性要求也越来越高。汽车产生的噪声有诸多因素,但汽车发动机的排气噪声在汽车整体噪声中大约占有30%的比例。人们在控制发动机的排气噪声时,如果仅控制噪声源减噪量是非常有限的。因此,最简单且最有效的减噪措施是在发动机排气系统上安装排气消声器。优良的消声器一方面可以大范围的减小内燃机多个频率的排气噪声,另一方面也不可让内燃机出现太大的功率损失。传统上,试验方法在消声器研究中是一个汽车噪声研究者的重要手段,然而,受限于试验成本的控制以及试验研究的较长周期,这些因素给研究者带来了很多不便。随着计算机的发展以及仿真技术在汽车方面的深入应用,GT-POWER在汽车性能的仿真计算方面得到了广泛的使用,大量的实践证明,利用GT-POWER在消声器的设计开发具备较高的可靠性,消声器前期的设计开发在一定程度上可以代替试验研究。本论文运用GT-POWER软件,针对某6缸涡轮增压发动机进行建立模型并仿真计算,首先进行了发动机动力性的标定过程验证模型的准确性。通过对发动机经常运行的转速段噪声进行分析,分析了1/3倍频程、各阶次噪声和尾管总体噪声图,探究其排气噪声源声学特性。按照消声器的设计原则,建立以及不断改进,从中优化得出一个排气消声器,以方案1为蓝本,改进出两种不同类型,建造消声器耦合柴油机时的模型以评价消声器降噪性能,并对其噪声性能进行了模拟分析。建立消声器的传递损失、插入损失和压力损失模型,并对3个相异类型消声器的进行了比较研究。同时考虑多个因素,依据仿真结果对方案1内部结构进行了改造,并通过对调整内部结构后的消声器的模拟计算,确立了消声器内部结构优化的原则。最后在综合考虑消声量和压力损失的前提下,仿真结果认为方案3的整体消声性能以及背压的效果是最优的,各项性能都可以满足其限制要求。
[Abstract]:With the rapid development of the automobile industry and transportation industry, people rely more and more on the automobile. Therefore, the number of cars in our country is increasing year by year. At present, the automobile noise control in the city is facing more pressure and challenge, at the same time, people have higher and higher requirements for the comfort of the automobile. There are many factors in the noise caused by the automobile. But the exhaust noise of automobile engine is about 30% percent of the total noise. When people control the exhaust noise of the engine, it is very limited if only the noise source is controlled. The simplest and most effective noise reduction measure is to install exhaust muffler on the engine exhaust system. On the one hand, the excellent muffler can reduce the exhaust noise of internal combustion engine with multiple frequencies in a wide range. On the other hand, the internal combustion engine should not have too much power loss. Traditionally, the test method is an important means of vehicle noise researchers in the study of mufflers, however. Limited by the control of test cost and the long period of experimental research, these factors bring a lot of inconvenience to researchers. With the development of computer and the application of simulation technology in automobile. GT-POWER has been widely used in the simulation calculation of automobile performance. A large number of practices have proved that the design and development of muffler using GT-POWER has a high reliability. To some extent, the design and development of muffler can replace the experimental research. In this paper, GT-POWER software is used to model and simulate a 6-cylinder turbocharged engine. Firstly, the veracity of the model is verified by the calibration process of engine dynamic performance. By analyzing the noise of engine running frequently, the 1/3 times frequency range, the noise of each order and the overall noise diagram of tail tube are analyzed. According to the design principle of muffler, establish and improve continuously, from which an exhaust muffler is optimized, and two different types of muffler are improved based on scheme 1. The model of muffler coupling diesel engine is built to evaluate the noise reduction performance of muffler, and its noise performance is simulated and analyzed. The model of transmission loss, insertion loss and pressure loss of muffler is established. At the same time, considering several factors, the internal structure of scheme 1 is modified according to the simulation results, and the muffler after adjusting the internal structure is simulated and calculated. The principle of internal structure optimization of muffler is established. Finally, the simulation results show that the overall performance of the scheme 3 and the effect of back pressure are optimal on the premise of comprehensive consideration of noise reduction and pressure loss. Each performance can satisfy its limit request.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U464.172;TB535.2

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