液态LPG燃料喷射过程的数值解析及可视化试验  

Simulation and Visualization of Liquid Phase LPG Spray

作　　者：许伯彦[1] 耿德强[1] 齐运亮[1] 刘红艳[2] 蔡少娌[3] 

机构地区：[1]山东建筑大学机电工程学院,山东济南250101 [2]济南铁道职业技术学院机械工程系,山东济南250013 [3]济南大学机械工程学院,山东济南250022

出　　处：《内燃机学报》2009年第2期146-152,共7页Transactions of Csice

基　　金：国家自然科学基金项目(50576047);清华大学汽车安全与节能国家重点实验室开放基金项目(KF2007-08);山东省自然科学基金项目(Y2006F02)

摘　　要：对原通用FIRE CFD软件中的喷雾模型进行了修正、在蒸发方程中增加了由于燃料过热度而引起的蒸发量变化的项之后,将喷嘴内部流动过程的解析获得的喷孔出口的实际流通截面积、压力、流速作为计算的初始条件,数值解析了液态LPG的喷雾发展过程以及在进气歧管模型内的反射过程。并且与光学纹影试验结果进行了比较,验证了解析方法的可行性。在这个基础上,进一步考察了不同喷射压力时的LPG喷雾贯穿距离和索特平均直径(SMD),在减压沸腾现象发生时,离开喷孔出口的液滴的索特平均直径(SMD)迅速地减小。当把电控汽油机直接改装成液态LPG喷射发动机时,应考虑反射的LPG-空气混合气到达进气歧管入口可能引起的各缸间吸气干涉的问题。The spray of liquid phase LPG （liquefied petroleum gas） and its reflection in intake manifold were simulated using FIRE CFD （computational fluid dynamics ） code. The code contains a modified evaporation equation which is added an item to describe the evaporation caused by superheat after the liquid phase LPG is injected out. The initial conditions used in the spray simulation including the effect flow area, the pressure and the velocity at the nozzle hole outlet are provided by the results of internal flow simulation. The simulation results are validated by comparing with the results from schlieren experiment. The variations of spray tip penetration and SMD under different injection pressures are investigated. The results showed that the SMD was reduced rapidly with flashing of the liquid phase LPG caused by superheat. Moreover, the intake interference between cylinders due to mixture reflection in intake manifold should be considered when a MPI gasoline engine was modified to run on liquid phase LPG.

关 键 词：液态LPG 喷雾 数值解析 可视化 

分 类 号：TK464[动力工程及工程热物理—动力机械及工程]