Four-Cylinder Diesel Engine Cooling System Based On CFD Simulation Analysis And Optimization Simulation

Diesel engine cooling performance is good or bad has been one of the important factors that restrict the development of diesel engine, the engine in the normal working under high temperature and heat load. Engine cooling system main function is through the cooling medium in the three dimensional flow in the cooling jacket engine extra high temperature heat away, to ensure that the engine can work in a suitable temperature environment Cylinder block as the engine heat load under key parts, which can withstand the intensity and reliability directly restricts the whole engine performance good or bad. At the same time, the engine cooling system cooling intensity is too big, too small will influence the cooling effect, make its work cannot reach the best effect To prevent the high temperature lead to insufficient cooling engine overheating phenomenon, and also to avoid the engine temperature is very low (winter or cold region) under the condition of excessive cooling phenomenon could occur. Therefore, research on diesel engine cooling performance is good or bad to improve its performance has a crucial influence.In this thesis, Quan Chai independent research and development of the latest QC4F1 3.8-liter four-cylinder diesel engine as the structural model, mainly study the key areas of cooling jacket and cooling, such as engine exhaust and cylinder head bridge of the nose area (into the exhaust valve seat and valve seat and nozzle area) between the cooling fluid flow situation. In this thesis, through the three-dimensional modeling software CATIA diesel engine cooling model was established, using numerical simulation software AVL FIRE simulation analysis of the model in a certain flow rate of cooling flow, the flow field of cooling of the three-dimensional flow field distribution, through the analysis of flow field distribution, to get the model exists insufficient cooling phenomenon, for the shortcomings of cooling area, by improving the model structure so as to further improve its cooling effect This paper main research work is as follows:(1) The method of using numerical simulation results of the simulation of engine cooling jacket to understand and master the cooling jacket model establishment method and the three-dimensional modeling software CATIA is used to establish a set of 3 d engine cooling water model, through the three-dimensional simulation software of CFD has set up a good model for grid division and post-processing work. Is analyzed, the results of the simulation analysis of cooling the engine cooling fluid in the chamber internal flow field distribution.(2) By improving the 4F1 model structure of the engine, can achieve the desired cooling effect, effectively improve the engine cylinder block and cylinder head in " the bridge zone " insufficient cooling of the phenomenon. In the original machine tests increase cooling fluid flow due to insufficient cooling fluid flow were improved or bad effect caused by flow resistance. Also prove the feasibility of using three-dimensional CFD simulation method, and the reliability of the test(3) Summarize the results of numerical simulation, and put forward the corresponding improvement methods, improve the cooling effect of the engine cooling system, as to provide theoretical basis for the follow-up development of engine cooling system.