Abstract
Design of an efficient cooling system has become critical for improving the reliability and durability of new generation engines. The stopper can be used in water jacket of cylinder block to provide the cross coolant flow to improve the cooling efficiency of water jacket. In this paper, a front and a rear stopper are used to organize the coolant flow inside the water jacket. Because of the inaccurate casting process , the actual gap area between stopper and water jacket wall , is much different from the design status . The wall temperature of 4th cylinder become higher than upper limit and the pressure loss of water jacket increases. Therefore the flow area which the fluid can pass through the stoppers can be adjusted by drilling holes with different radius on stoppers. In this way, the gap area changes caused by casting can be compensated. The results show that the wall temperature decreases and the overall pressure loss of water jacket is reduced. The way proposed by this paper, which drilling holes on stoppers, can be carried out conveniently in manufacture process. The quality can also be warranted. The sensitivity analysis of gap area which affect the cooling performance of water jacket is then carried out to make sure the improved design of water jacket has reliable and stable cooling ability.
KEYWORDS –Internal combustion engine, water jacket, stopper, cooling performance, sensitivity analysis