二冲程汽油机扫气过程的CFD数值模拟与试验研究  

Simulation of Scavenging Process in Two-Stroke Gasoline Engine

作　　者：陆军[1] 沈辉[1] 涂强[1] 景陶敬 

机构地区：[1]扬州大学机械工程学院,江苏扬州225127

出　　处：《农业装备技术》2017年第1期18-22,共5页Agricultural Equipment & Technology

摘　　要：利用CFD软件FLUENT对1E40F型小型汽油机的扫气过程进行数值模拟,通过对不同扫气道结构的扫气道内流场进行研究,发现活塞顶的形状对内流场会产生一定影响。由于扫气口对称,在内流场形成过程中会出现对称的环流与滚流,且在靠近扫气口下部会出现径向涡流,这在一定程度上不利于废气排出,并出现新鲜工质短路损失。将原机活塞圆形凸顶改为凹坑阶梯形,计算发现缸内气体流动更加有序,短路损失相对降低,试验结果表明,改形的活塞顶对发动机的动力性、经济性和排放性都有很大改善。In this paper,simulation of the scavenging process in a two-stroke engine was used to the small engine 1E40F by a great CFD software called FLUENT. Through the study of the internal flow field in the different swept airway structure , it is found that the shape of the piston crown has a certain influence on the flow field in the process of scavenging. In the course of the formation of the inner flow field, the symmetrical circulation and the rolling flow can occur because of symmetric scavenging ports,and in the lower part of the scavenging port will appear near the radial vortex,which is not conducive to the discharge of waste gas to a certain degree.And there is a short circuit loss of fresh work. The circular convex top piston of the original machine is changed into the pit step piston. The calculation results show that the gas flow in the cylinder is more orderly and the short circuit loss is reduced. As can be seen from the test results, the engine＇s economy and emissions are greatly improved.

关 键 词：二冲程汽油机 扫气过程 数值模拟 新鲜工质 

分 类 号：TK411[动力工程及工程热物理—动力机械及工程]