后置客车发动机舱温度场试验

Experimental Study on Temperature Field and Influences in the Rear Engine Compartment

摘要:

针对后置客车发动机冷却系统散热不良的情况，通过客车道路试验，实测了后置发动机舱空间各点温度分布情况，并分析了温度场分布的原因。对比了在不同车速下，百公里油耗和发动机舱温度场分布的关系，分析温度场分布随车速变化的规律。指出在保证冷却系统冷却能力的情况下，冷却空气流量与散热器散热量成正比。并利用场协同理论，分析发动机舱内流场和传热特性，指出发动机舱内布置要减少涡流并尽量使温度梯度与流动方向一致。

Abstract:

The temperature field in the rear engine compartment was measured and its cause was analyzed with the bus road test for defective cooling system in the rear engine compartment. The relationship between temperature field and brake specific fuel consumption at different bus speeds is compared. The comparative study results explains why the temperature field changes with bus speeds and indicates that when the cooling capacity of the cooling system is large enough, the air mass flow of cooling air is in proportion to the heat release of the radiator. Flow field and heat transfer characteristics are analyzed in engine compartment according to the field synergy principle. A proposal is put forward to try out decreasing vortex and keeping the direction of flow and temperature gradient consistent in the arrangement of rear compartment.