文档介绍：华中科技大学
硕士学位论文
直喷式涡轮增压汽油机工作过程分析及匹配研究
姓名:白亚鹤
申请学位级别:硕士
专业:动力机械及工程
指导教师:陈国华
20090501
华中科技大学硕士学位论文
摘要
本文对自然进气汽油机采用废气涡轮增压技术进行了匹配及工作过程数值
分析研究。文中对其燃油喷射方式进行改变,即由进气道喷射改为缸内直喷。根据
涡轮增压的要求,为该机型重新设计了排气系统,并对新设计的排气系统进行了三
维流动数值模拟及其性能进行了评价。
文中,在气道喷射自然吸气发动机的基础上,以 AVL-BOOST 软件为工
具,建立全模式的涡轮增压缸内直喷汽油机模型。以新建立的模型为基础,对涡轮
增压器与缸内直喷汽油机进行了匹配,绘制了发动机与涡轮的联合运行线,分析了
涡轮增压器的效率和涡轮的通流量情况。计算了新的涡轮增压发动机的主要性能指
标,与原机型进行了对比分析。此时,分析了一维模拟计算条件下排气管压力分布
情况,为涡轮增压发动机的三维模拟设计提供了边界条件。
利用 Pro/Engineer 软件在原排气管的基础上重新设计了新的排气系统三维模型。
采用 FLUENT 软件的前处理程序 GAMBIT 对模型进行了网格自动生成。采用
FLUENT 软件,选取整个排气循环的几个特征位置进行三维数值模拟,分析不同缸
排气时排气管内的流场状态,为涡轮增压发动机排气管设计提供了依据。
文中,还将汽油机废气涡轮增压系统工作过程模拟、匹配与实验结果进行
了对比分析。为直喷式汽油机涡轮增压系统设计提供了重要参考。

关键词: 汽油机涡轮增压排气管三维设计三维流动模拟
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华中科技大学硕士学位论文
Abstract
The power improvement with exhaust gas turbocharger of a naturally aspirated
gasoline engine was studied in this paper, and the way of fuel injection was altered from
intake manifold injection to direct injection (DI) in cylinder. The matching and
performance of the turbocharger and gasoline engine were analyzed, and the
three-dimensional numerical simulation of the designed exhaust gas system was carried
out, on the meanwhile, the performance of exhaust gas system was evaluated.
plete model of DI gasoline engine with turbocharger was designed with
AVL-BOOST based on the intake manifold injection and naturally aspirated gasoline
engine. The turbocharger and DI gasoline engine was matched, and bined
operation line was drawn to analyze the efficiency of the turbocharger and gas flow
characteristics of the turbine. The main performance index of the turbocharged engine
were calculated pared with the original model, and one-dimensional pressure
distribution of the exhaust gas pipe was analyzed to obtain boundary conditions for
three-dimensional numerical simulation.
A three-dimensional model of new exhaust gas system was designed using
Pro/Engineer. The model mesh was aut