柴油机冷却水套空化两相流三维瞬态数值模拟研究  

3D Numerical Simulation of Cavitation Two-Phase Flow in Cooling Water Jacket of a Diesel Engine

作　　者：林杰威[1,2] 李宇寒 刘泉 黄鹏 王西博 张俊红 LIN Jiewei;LI Yuhan;LIU Quan;HUANG Peng;WANG Xibo;ZHANG Junhong(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China;Weichai Power Co.,Ltd.,Weifang 261061,China;State Key Laboratory of Engine Reliability,Weifang 261061,China;Tianjin Ren'ai College,Tianjin 300072,China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]潍柴动力股份有限公司,潍坊261061 [3]内燃机可靠性国家重点实验室,潍坊261061 [4]天津仁爱学院,天津300072

出　　处：《内燃机工程》2021年第4期84-92,共9页Chinese Internal Combustion Engine Engineering

基　　金：内燃机可靠性国家重点实验室开放课题(skler-201902)。

摘　　要：为了深入研究柴油机湿式气缸套振动引发穴蚀的机理和影响因素,在水套内部冷却液流动稳态数值模拟得到冷却液压力场与速度场的基础上,以完整单缸水套为研究对象,提取6缸稳态模拟结果作为边界条件。基于Mixture多相流模型与Singhal完全空化模型,采用动网格技术建立柴油机冷却液空化数值模拟的气液两相流仿真模型,进行冷却液空化瞬态数值模拟。计算结果表明:振动导致的冷却液对壁面的脉冲压力是缸套穴蚀的主因,冷却液脉冲压力幅值随壁面振动速度升高而增大,在6.75°即振动速度最大时刻出现最大脉冲压力。在柴油机一个工作循环内,缸套主、次推力侧均有可能发生穴蚀现象,其中主推力侧发生穴蚀现象的可能性更高,且存在4个易发生穴蚀的区域。按壁面所受脉冲压力幅值进行排序,发生穴蚀可能性由大到小依次为主推力侧的中上部、顶端、中下部及底端。最后从抑制振动、缸套表面改性处理和降低脉冲压力角度提出了降低穴蚀风险的措施。In order to deeply study the mechanism and influencing factors of cavitation caused by the vibration of diesel engine wet cylinder liner,based on the steady-state numerical simulation of the coolant flow inside the water jacket to obtain the coolant pressure field and velocity field,the complete single cylinder water jacket was taken as the research object,and the six cylinder steady-state simulation results were extracted as the boundary conditions.Based on the multiphase flow model Mixture and the full-cavitation model Singhal,a gas-liquid two-phase flow simulation model for the numerical simulation of diesel engine coolant cavitation was established to carry out the transient numerical simulation of coolant cavitation.Results show that the pulse pressure of the coolant on the wall caused by vibration is the main cause of cylinder liner cavitation.The amplitude of the coolant pulse pressure increases with the wall vibration speed.The maximum pulse pressure appears at 6.75°when the vibration speed is the maximum.In a working cycle of the diesel engine,cavitation may occur on the main and secondary thrust side of the cylinder liner.And it is more likely to occur on the main thrust side.There are four areas on the main thrust side prone to cavitation,i.e.the upper middle,the top,the lower middle and the bottom from the greatest possibility to the lowest possbity of cavitation sorted by the amplitude of the pulse pressure on the wall.Finally,measures to reduce the risk of cavitation are proposed from the perspective of vibration suppression,cylinder liner surface modification and impulse pressure reduction.

关 键 词：气缸套 空化 两相流 数值模拟 脉冲压力 

分 类 号：TK422[动力工程及工程热物理—动力机械及工程]