动静干涉对涡轮转子叶片气膜冷却的影响

为研究动静干涉对涡轮转子叶片气膜冷却效果的影响,选取AGTB涡轮叶栅作为研究对象,匹配前排导叶并对整级叶栅进行非定常数值模拟。对不同时刻流场截面的流动情况以及叶片表面温度随时间的演化规律进行了详细的分析,此外,总结了尾迹和势干涉对下游叶片气膜冷却的影响。主要结论如下:导叶强烈的势干涉作用在幅值为12°的范围内改变下游叶片的入射角,对冷却射流有非常大的影响;尾迹和势干涉作用诱导冷却射流的"上扬"现象,并使其冷气流量增加20%以上,有利于提高瞬时的冷却效果;势干涉对前缘冷却射流的作用时间约为1/2个静子周期,尾迹的作用时间约为1/6个静子周期,前者作用时间长,且效果更强。受到输运效果的影响,整个叶片冷却效果的变化与气膜孔射流状态的变化不是同步的,滞后时间可达1/3个静子周期甚至更长。 

Effect of rotor-stator interaction on film-cooling of turbine blade

For the purpose of studying the effect of rotor-stator interaction on film-cooling of turbine blade, the AGTB turbine cascade was chosen to do the research, with which a vane row was assembled. Unsteady numerical simulation was made for the full stage. The cross-section flow field at different instants of time and variation of temperature distribution of the blade over time were analyzed in detail. Furthermore, influence of wake and potential interference on film-cooling of downstream blade was discussed. Conclusions are as follows: the strong potential interference of the vane could change the flow angle of downstream blade in the range of 12°, which has a great influence on cooling jet; both the wake and potential interference could induce cooling jet "uptrend" and increase the mass flow of the cooling air by more than 20%, enhancing instant cooling performance; function time of potential interference was about 1/2 stator period, while that of the wake was about 1/6 stator period, and the potential interference usually performs longer time and has stronger effects than the wake. Affected by the transport effects, variations of cooling performance of the whole blade and flow condition of cooling jet were not synchronous, of which the latency time could be about 1/3 stator period or even longer.