Flow Field And Cooling Characteristics Analysis Of Water Jacket In Engine Cylinder Head

As part of the combustion chamber, cylinder head endures high heat and mechanical loads in the process of engine working, it is one of the worst working conditions and most important cooling components. The cooling effect of cylinder head is a very important signification for working reliability and comprehensive properties of the engine.In this paper, the author takes the cooling water jacket in the cylinder head of an aero gasoline engine as the research object. Using CFD software as the research tool, through coupled fluid-heat simulation, the flow field and cooling characteristics of the cooling water jacket are analyzed.The geometric models of cylinder head and cooling water jacket are established for numerical simulation, mesh generation method is determined by computing the mesh independence, and the boundary condition are discussed. This paper summarizes the evaluate principle for water jacket, analyzes the flow field of water jacket of a wide range of working conditions, calculates the warm-up time of the cylinder head and cooling system in the cold environment. The results show that, the cooling water jacket can fully meet the cooling requirements for heat load on the cylinder head under the normal take off,maximum endurance,high temperature,and cold environment, there are also some insufficiencies in the geometric models.This paper analyzes the effects of inlet conditions,external environmental factors,physical parameters of the cylinder head and the water jacket,wall roughness on the flow field of the water jacket under steady conditions, their influence law are given and are taken as an important basis of the organization and control of the cooling on the development of aero engine. Integrated analysis system for the flow field of the water jacket based on Matlab has been established, the system is verified,improved, and a curve relation which provides some reference for the selection of inlet conditions of the cooling water jacket between inlet temperature and pump flow established by the integrated analysis system.Structure improvement for the water jacket according to the analysis results about the flow field has obvious effect, improved cylinder head and water jacket can provide more homogeneous and reasonable temperature distributions, but smaller consumed power.