Numerical Simulation And Optimization Study Of The Gasoline Cooling Jacket Performance

With continual enhancement of the gasoline engine, heat transmission and thermal load of the cylinder block and cylinder head have become an important factor in engine combination performance. Develop a small flow resistance, excellent heat transfer performance of the cooling water jacket is very important. This can decide that the gasoline engine whether can also as major impetus in the 21st century transportation and communications. Therefore, heat balance analysis of the cooling water jacket, flow field analysis of the cooling water jacket and performance optimization are very important to maintain the suitable operating temperature of gasoline engine components. This can ensure its work reliability and good performance, and also important to achieve emission reduction targets.This paper is based on the second phase“985”of Hunan University - design and manufacture of advanced technology automotive technology innovation platform (Teachings letter [2004] No. 1). In order to improve the gasoline engine’s power performance, fuel economy, emission performance, reliability and durability. The main work is as follows.(1) Equation of gasoline engine cooling water heat balance has been established. Then factors affecting the heat transfer have been analyzed. It can provide a good theoretical basis to the engine cooling water design.(2) A four-cylinder gasoline engine cooling water flow field has been simulated and analyzed. The results show that this four cylinder gasoline engine cooling of design quite to be reasonable jacket by the analog computation analysis, and can meet the cooling effect that design requirements, but also has the place which need some optimize. It is negative to the cooling of local part. Water amount on the exhaust valve side of cylinder head is low, and it is also negative to the cooling of this part. The pressure loss is large on cylinder head and engine cylinder gasket.(3) To counter the problems existing in the cooling jacket, the corresponding prioritization scheme has been put forward. First, Increase water holes diameter between the first and second cylinder to improve the cooling capacity of this area. Second, move the intake valve side water hole position of third and fourth cylinder to the outlet side. This can avoid the impact of the water around this area and prevent the formation of dead flow. At last, increase the water hole diameter of exhaust side to strengthen the cooling capacity of this area. The optimized results show that the cooling water jacket can achieve a better cooling effect.