摘要
采用台架试验与计算流体力学(CFD)数值模拟相结合的方法,对某款汽车排气系统进行结构优化,以降低其排气背压。根据台架试验结果,划分了原排气系统中紧耦合催化转化器、二级催化转化器、主消声器和副消声器等各部件对整个排气背压的贡献量。通过CFD数值计算,详细分析了原排气系统中的流动特性,找到各部分排气背压的产生原因。结合台架试验和CFD的分析结果,对原始方案进行了针对性的结构优化。优化方案的排气背压比原始方案的排气背压平均下降了40%左右,最大排气背压由原来的90 kPa下降到改进后的51 kPa左右,达到了设计要求。
The structural optimal designs aimed to decrease the high back-pressure of a vehicle exhaust system were accomplished with the bench test and computational fluid dynamics （CFD） simulation. Based on the results of bench test for the primary exhaust system, contributions from the close coupling catalytic converter, the two-stage catalytic converter, the main muffler and the auxiliary muffler for the whole back-pressure were classified. And the flow characteristics of the primary exhaust system were also analyzed in details by CFD simulation, which revealed the main reasons of the high exhaust back-pressure. Based on the results of the bench test and the CFD simulation, a series of directed designs for the exhaust system were proposed. Therefore, back-pressure of the optimal exhaust system decreases by 40% averagely than that of the primary one. The highest exhaust back-pressure decreases from 90 kPa to 51 kPa.
出处
《内燃机学报》
EI
CAS
CSCD
北大核心
2007年第4期358-363,共6页
Transactions of Csice
基金
天津市科委科技攻关项目(043185111-8)
天津市应用基础研究计划项目(07JCYBJC06700)
关键词
排气系统
计算流体力学
优化设计
Exhaust system
Computational fluid dynamic
Optimal design
