Study On The Fluid-solid Coupling Heat Transfer Of The Diesel Engine Cylinder Head

The cylinder head is one of the main components of the most complex structure in the internal combustion engine, for sealing the top of the cylinder, and the top surface of the piston and the inner wall of the cylinder together to form the space of the combustion chamber, which in diesel engine working process, the environment is very hard, not only directly under high temperature and high pressure generated by the burning of fuel, but was also deeply influenced by internal coolant flow. With the continuous improvement of intensification of diesel engine, the key components for improving the performance of diesel engines have become increasingly demanding, cylinder head heat load and heat transfer problems become more and more the focus of attention of researchers at home and abroad. Therefore, based on the fluid-solid coupling method of diesel engine cylinder head heat transfer Research for analysis of cylinder head heat load and improve the diesel engine parts performance with great significance.In this paper, through a lot of access to relevant documents, according to the research status of domestic and foreign diesel engine cylinder heat transfer, a medium-sized four cylinder diesel engine as the research object, the finite element was established in diesel engine combustion chamber and cooling system model, through CFD software AVL-FIRE to complete the three-dimensional numerical simulation of combustion process and cooling system in cylinder calculation, analysis and evaluation the heat transfer coefficient and temperature distribution of cylinder combustion chamber space, the flow distribution of cooling system and the temperature distribution of cylinder head water jacket, at the same time obtain thermal boundary conditions of cooling water jacket and cylinder wall contains thermal heat transfer coefficient and temperature information; establish the three-dimensional geometric model of cylinder head of diesel engine, by using the finite element pre-processing software Hypermesh into the finite element model, by the mapping function of AVL-FIRE software to map the thermal boundary conditions on the cylinder head surface finite element mesh to obtain file containing the boundary conditions, for subsequent cylinder head temperature field coupling calculation; Finally, using the theory of finite element analysis software ABAQUS coupled calculation, through the fluid-solid coupling method, several iterations, to be close to the actual cylinder head temperature field distribution of a heat transfer wall and diesel engine cylinder head coolant in the combustion gas coupling effect.The hardness plug thermometry is used for cylinder head temperature field measurement test, validity of the calculation results with the temperature measurement data comparison and verification simulation. The results show that the temperature field distribution of diesel engine cylinder head is reasonable, the highest temperature is far lower than the limit working temperature of the material. This research work in this paper has a certain rationality significance for analyzing the temperature distribution of diesel engine cylinder head.