柴油机气缸盖多场耦合分析及冷却性能影响因素分析

Multi-field Coupling Analysis of Cylinder Head of Diesel Engine and Analysis of Factors of Cooling Performance

通过热流固耦合分析方法,对某柴油机缸盖的温度场、耦合应力场进行了分析,并通过试验对计算结果进行验证。在此基础上,对缸盖冷却性能的影响因素进行分析。结果表明:入口质量流量在一定范围内变大,能够显著降低缸盖的最高温度,但质量流量继续增大时,冷却效果变化不明显;入口温度值的高低对缸盖最大温度影响效果较为明显;在大于层流层厚度范围内增大粗糙度,可降低缸盖的最高温度值,但效果不显著。

The temperature and coupling stress of the cylinder head of a diesel engine are analyzed by the thermal fluid-structure interaction,and the calculation results are verified by experiments. On this basis,the influencing factors of cooling performance of cylinder head are analyzed. The results show that the maximum temperature of cylinder head can be obviously reduced by increasing the inlet mass flow rate of coolant within a certain range,but the cooling effect is slow when it continues to increase. The inlet temperature has a significant effect on the maximum temperature of cylinder head. Only when the roughness is greater than the thickness of laminar layer can the maximum temperature of cylinder head be reduced,and the effect is not obvious.