近距离散冲击射流换热实验研究

EXPERIMENTAL STUDY ON HEAT TRANSFER OF SEPARATED IMPINGEMENT JETS IN SHORT DISTANCE

涡轮叶片内的冲击换热多取近距离散冲击换热 (冲击距与喷孔直径之比 Zn/dn<3,喷孔中心距与喷孔直径之比 Cn/dn<3)。由于在叶片前缘有气膜出流孔 ,因而对叶片内前缘冲击换热做大面积平均实用意义较小。所以本实验旨在总结近距冲击下驻点连线及驻点附近小面积的换热规律并得出新的经验公式 ,这具有较大的实用意义。

In actual cooling construction of turbine blade the relative distance between circular jets c n/d n is less then 3 and the relative distance of nozzle exit to target surface is also less than 3.But the available empirical formulas were achieved on the basis of very large range of these geometric parameters.Obviously,these formulas may be inaccurate in the practical narrow range of th ese paremeters,in particular when the temperature of the turbine is very high,and on the surface of the blade exist many rows of film co oling holes.So an experimental research on the heat transfer of impingement jets has been carried out in the actual range of the geometric parameters and new empirical formulas have been established,which can be applied to the turbine blade o f the advanced aeroengine.