The Flow And Fluid-Solid Coupled Heat Transfer Analysis Of A Diesel Engine Cooling System

With the development of society, people put forward higher demand to the more economic and higher power engine. High pressure and high compression ratio engine technology has become development trend in the future. The engine strength has been increased. The risk of failure caused by the heat load of the motor also has become more and more high. Therefore, in order to keep the engine work normally, the better cooling of the heated parts of the engine becomes critical. The "high temperature cooling" and "accurate cooling" will become the development direction of the engine cooling system, which requires the design of engine cooling water jacket more reasonable.At present, more and more people using the method of fluid-solid coupled simulation to study the heat transfer of internal combustion engine. The surface which solid and flow contact with each other has become internal boundary of the system by using the fluid-solid coupled simulation method. And we can get the temperature field of the solid and flow by calculating the heat transfer of the coupled surface. It is better to take the method of fluid-solid coupled simulation as a judgment standard quality of cooling effect accords with the actual working state of engine, compared to the velocity of flow of cooling water.Because what we researched is a16cylinders diesel engine, the model is very complex, The fluid-solid coupled calculation requires very high performance of computer. Therefore, we firstly established a3D model of the cooling water for the16-cylinders diesel engine, and used CFD software named FLUENT to calculate and analyze it. In this way, the wall boundary was set to be adiabatic. We has got much flow data such as the flow velocity of cooling water, the flow pressure and so on. And then we made a preliminary assessment of the cooling effect on the basis of the above information.Because each cylinder cooling water jacket is arranged in parallel, each cylinder structure is consistent and relatively independent, we established a3D coupled heat transfer model which was made up of cylinder head, cylinder liner and cooling water. And then we did the solid-flow coupled heat transfer simulation. The inlet and outlet boundary data of the water was loaded by the integral water simulation. And accurate and intuitive temperature field distribution of each component was obtained. The calculation results show that, the simulation results were in good agreement with experimental data, which provides a basis for the optimization design of diesel engine cooling water jacket...