CFD Analysis Of Cooling System And Cylinder Head Heat Transfer Of A Diesel Engine

In recent years,due to the power of diesel engine rising,the heat load of the components is also increasing.Therefore,the design of an efficient cooling system together with good thermal efficiency for a new engine is becoming a critical task.In contrast,numerical simulation is time-saving and labor-saving,so an accurate and fast simulation of the engine cooling system is essential.In this paper,in order to reduce the amount of calculation,the flow simulation of the whole 6 cylinder model is carried out.In the whole simulation,FLUENT is used to analyze the whole flow only by CFD.The appropriate grid size should be used in the pre-processing,and the appropriate grid can not only ensure the accuracy of the results,but also greatly reduce the computation time.Through the overall simulation results,we can conclude that the overall flow rate is greater than 1m/s,the overall speed is much greater than the design requirements.However,at the end of the inlet pipe,the flow effect is poor.In this paper,the shape of the inlet pipe is improved,and its influence on the flow is analyzed.From the results of the simulation,the worst sixth cylinder is selected.Thirdly,the cylinder head,cylinder liner and water jacket of the sixth cylinder are re refined and processed locally,and the fluid solid coupling model is established to analyze the heat transfer and flow.In order to get the stress distribution inside the cylinder head,the Workbench software is used to calculate the thermal stress mechanical stress of the cylinder head.In order to ensure the results more in line with the actual situation,through the data sharing between CFD analysis and FEA analysis,accurate thermal boundary conditions are obtained.The maximum stress value of the calculated results is 179.4Mpa,and the yield limit of the material is 220 Mpa,and the strength of the cylinder head can be determined by the fourth strength theory.