Simulation Optimization And Experimental Research Of The Engine Cooling System

With the rapid development of engine industry,the traditional research and development process lack of scientific theoretical calculation causing the problems of high rejection rate,high experimental cost,and long development period,which have been unable to meet the needs of modern enginedevelopment and market update.Using of CAE simulation technology could forecast the performance of the engine in the stage of the engine drawings,which is important to reduce the amount of engine scheme in the test.In this paper,P type engine was used as the research object,the engine cooling jacket and the vehicle thermal equilibrium are analyzed and optimized.In this study,the main content includes:First of all,it is very important of the reasonability of the design for cooling water jacket to the effect of engine cooling.The software FIRE was used to CFD simulate' for three kinds of water jacket structure.The calculation scheme was comparison of the three water jackets:the original plan,plan 1 and plan 2.The first plan was changing the channel between the intake and exhaust to a cross hole with diameter 3.5mm;the holes on the front of the cylinder head 1,cylinder 2 were canceled,and the holes on back-end of cylinder head 1,cylinder 2 were increased,and the holes on exhaust side were larger than that of intake side.Plan 2 was also changing the channel between the intake and exhaust to a cross hole with diameter 3.5mm;but the water holes on the front of the cylinder head were retained,the diameters of holes from front to back-end were gradually increased,and the holes on exhaust side were larger than that of intake side.The calculation results were shown that:the water jacket flow effects of exhaust side for plan 1 and plan 2 were improved compared with the original plan,and that of intake back-end side were improved.But some dead points were appeared on the front of inlet side in the plan 1 due to the holes on the front cancellation.Compared with the original plan,the water jacket flow distribution in the cylinder head of front-end was more uniform for plan 1 and plan 2.But the water jacket flow effect on the back-end cylinder head become worse for plan 1,because the flow velocity decreased.From the above,plan 2 was better.So the plan 2 was selected for design of P type diesel engine water jacket.Then,the compositions of the automobile cooling system and the effects on automobile cooling system were studied.A vehicle,equipped with P type engine,was analyzed the thermal balance using the Flowmaster and FlowmasterAVS sofwares.The results were shown that,the cooling package could meet the match of vehicle cooling system.Finally,the P type engine were matched with a vehicle cooperating with automobile factory,and then conducted a vehicle thermal balance test for cooling system through the CAE simulation technology to finally confirm.The results of real vehicle test showed that the vehicle cooling system could meet the demands of matching,and the test conducted one years later also showed that the vehicle cooling system also can meet the demands of matching,which proved that it was reasonable for CFD simulation calculation in this paper,and it greatly improved the rate of one-time success for matching.The results showed that:good effects have been achieved in this respect of the design of P type engine cooling system and the matching between P type engine and vehicle cooling system through the application of CAE simulation technology.The using of CAE simulation technology greatly decreased the development period,and it also greatly improved the rate of one-time success for matching with vehicle.It provided a reference for the development of the engine cooling system and the matching between the engine and the vehicle cooling system.