Integrated Exhaust Manifold Cylinder Head Design And Fluid-solid Coupling Heat Transfer Analysis

Compared with the common engine,the integration of exhaust manifold into cylinder head can achieve the goal of engine lightweight and integration,saving cost and reducing emission.When the engine is working with high load,the coolant can absorb part of the heat from the high-temperature exhaust gas in the integrated exhaust manifold duct,accelerate the speed of warming up engine and reduce fuel consumption,which helps the engine to meet more and more stringent environmental regulations.In this paper,firstly,the simulation of the water jacket of a gasoline engine is carried out,and it is found that the flow distribution of coolant is reasonable,but the flow velocity of the coolant near cylinder 1 and cylinder 2 is relative low.Then,the temperature field test of the cylinder head is carried out.The results show that when the engine is at 5500 rpm full load and water outlet temperature of cylinder head is 115?,the temperature of the bridge area of the exhaust valves of cylinder 1 is 248.5?,and the heat exchange of the water jacket meets the requirement.Then,the cooling water jacket structure of cylinder head with integrated exhaust manifold is designed and CFD flow simulation is carried out.The simulation results show that the flow velocity of the coolant near cylinder 1 and cylinder 2 is as low as that of the original cooling water jacket,so the fluid structure coupling analysis is necessary.When the finite element model of the integrated cylinder head is established,the mesh of the combustion chamber,the intake port and exhaust port,the valve seat are refined and encrypted.The results of fluid structure coupling analysis show that the highest temperature is 249.7? in the bridge area between exhaust valves of cylinder 1 with the boundary conditions of the original engine.Using ABAQUS software,loading thermal boundary conditions and constraints,the stress analysis of the integrated cylinder head is carried out.The maximum stress of the calculation result is 172.2MPa.According to the fourth strength theory,the integrated cylinder head meets the strength requirements.