不同转速对动叶传热影响的数值模拟

Effect of rotor speed on heat transfer of blades:numerical simulation

为了研究尾迹脱落频率对动叶传热及其气膜冷却效率的影响,采用SSTk-ω紊流模型,在Simple算法基础上,利用有限体积法对无气膜孔和前缘有3排气膜孔情况下,转速分别为500,1 000,2 000r/min时动叶表面的努赛尔数(Nu)分布进行数值模拟。结果表明:随着转速的增大,无孔和有孔时的冷却效果差异明显,无孔时随转速增加动叶压力面和吸力面Nu逐渐降低,传热效果较差,有孔时则相反,换热增强,冷却效果较好。

To investigate the effect of vertex shedding frequency on heat transfer and gas film cooling of the rotor blade,on the basis of Simple algorithm,the SSTκ-∞ turbulence model and finite volume method were adopted to discrete the control equations. Under conditions with no film-cooling hole and three rows of film-cooling holes at front edge of the blade, the effect of rotor speed on gas film cooling performance was numerically studied. The rotor speeds of 500 r/min,1 000 r/min and 2 000 r/min were selected as the simulation conditions. The Nusselt number distribution on rotor surface was obtained. The results show that, with the increasing rotor speed,there＇s dramatic difference in cooling effectness between the blade with no film-cooling hole and the one with three rows of film-cooling holes. For the rotor with no film-cooling hole, the Nusselt number on pressure side and suction side of the rotor reduced gradually with an increase in rotor speed, so the heat transfer performance was relatively poor. While for the rotor with three rows of filmcooling holes, the heat transfer was enhanced and the film cooling efficiency was higher.