Analysis and optimization of heat dissipation performance of an engine cooling water jacket
To accurately assess the heat exchange performance of the engine water jacket,computational fluid dynamics(CFD)simulations are conducted using AVL FIRE software to analyze the flow rate and heat transfer coefficient of the water jackets in the cylinder head and engine block of an engine.The simulation results indicate that the flow rate on the exhaust side of cylinder 4 is relatively lower than that of other cylinders,and the heat transfer coefficient of some areas is insufficient to meet the evaluation standards.The coolant flow rate at the rear flange of the integrated exhaust manifold on the cylinder head is low,resulting in minimal coolant flow in the lower water jacket,creating a dead zone for flow.At a coolant flow rate of 136 L/min,the flow resistance of the engine water jacket is 42 kPa,which is relatively matched to an electronic water pump with a power of 450 W,indicating high flow resistance in the water jacket.By increasing the cross-sectional area of one water hole in the cylinder head gasket by 80%and adding another water hole,while reducing the cross-sectional area of another water hole by 10%and increasing the flow length of the blocking rod by 150%,the flow between the upper and lower layers of the water jacket at the rear end of the exhaust manifold is optimized using a cup-shaped plug.CFD analysis and fluid-structure interaction analysis of the optimized water jacket are conducted,showing that at a coolant flow rate of 136 L/min,the water jacket flow resistance is reduced to 35 kPa,meeting the power requirements of the matched electronic water pump.After optimization,the coolant flow in the lower water jacket of cylinder 4 is significantly improved.Although the heat transfer coefficients in the nose area at the rear end of the intake and exhaust valves of cylinders 2 and 3 are still low,the maximum temperatures of the cylinder head and block met the specified limits.
water jacketheat transfer coefficientflow resistancecoolingengine nose area
万方数据
维普
