圆弧腔内有气膜孔的多排射流冲击传热试验研究

在燃气涡轮叶片中,常常在内腔采用冷空气射流冲击热壁,和把冷空气从气膜小孔排往叶片外表面,形成冷气膜,冷却和保护叶片,以便提高燃气温度,改善发动机的性能。对于叶背内腔的多排射流冲击冷却,上游射流沿腔壁流动所形成的横流会影响到下游排孔的冲击射流;同时还具有受冲击的壁面是弧形的及沿弧腔一般存在气膜出气孔的特点。本文针对这两项因素进行了模拟试验,与新近获得的平直腔冲击传热试验结果作了比较。结果表明,这两项因素均有利于提高内部冷却效果。

EXPERIMENTAL INVESTIGATION ON HEAT TRANSFER CHARACTERISTICS FOR ARRAYS OF CIRCULAR JETS IMPINGING ON CURVILINEAR SURFACE WITH CROSSFLOW AND EJECTION HOLES

The effects of curvilinear surface with ejection holes on the internal heat transfer coefficient of arrays of impinging have been investigated for simulation of the impingement cooled turbine vanes. The experiments show that boththe curvature of the surface and the presence of the ejection holes are in favour of the heat transfer augmentation. It is noted that the internal impingement heat transfer coefficient on the suction side of the cooled blade calculated by using the correlation of that on flate plate is more or less too conservative.