Heat-Fluid-Solid Multi-Field Coupling Analysis Of A 8-Cylinder Diesel Engine Cylinder Head

Today, the design of diesel engine is moving forward with extremely high load. It requires higher output power, smaller volume, lighter weight, which makes the structure of the diesel engine under greater thermal load and mechanical load. Accurately design and control of cooling performance and strength performance is becoming very important. To compare with experimental study, numerical simulation is more convenient, faster, and economy, which has been validated for many years, the results are reliable. It has become an important method for the design of the diesel engine.This research based on a 8 cylinder diesel engine overall water jacket and cylinder water jacket, cylinder head and cylinder liner. Use FLUENT and ANSYS-Workbench, to realize the co-simulation of multi-field coupling from the fluid-solid coupling to the thermal-mechanical coupling, and made research on structural improvement.Firstly, using Pro/E to make the necessary treatment of geometric model, and using ICEM to generate the computational grids. Then analyzed the cooling water jacket by using FLUENT, the simulation results are compared with experimental results for verifying. Studied the inlet duct length, which may influence the cooling water flow rate distribution. And found that extend the appropriate length, can effectively balance the cooling water flow rate. And then selected the 8th cylinder, did simulation of fluid-solid coupled heat transfer analysis by using FLUENT, and put forward to change two of the water holes into tangential holes. Made comparison of the cooling effect. Found that the changes increased the average velocity and the heat transfer coefficient, the local flow condition is improved. Finally, the temperature field calculation results of the cylinder head from the fluid-solid coupled heat transfer analysis was imported into Workbench, combined with mechanical load like the gas explosion pressure and bolt pre-tightening force, calculated the stress of the cylinder head. The calculation results show that the stress meets the strength requirement of the cylinder head.