涡轮叶片复合冷却的实验研究

按照涡轮叶片复合冷却的全过程 ,本文由三部分组成。首先 ,研究了冲击射流对复合冷却叶片前缘内壁的冲击—对流冷却 ,从而整理出在驻点处的内换热系数经验公式以及沿前缘内壁的换热系数变化规律。其次 ,研究了由于从气膜孔喷出的射流引起的气膜冷却效果在不同的吹风比下沿前缘外壁的变化规律。第三 ,由于气膜射流对主流的扰动作用 ,造成了传热的强化 ,由此 ,本文整理出一组局部外换热系数的经验关系式

EXPERIMENTAL INVESTIGATION ON COMPOSITE COOLING OF A TURBINE BLADE

In view of the whole process of composite cooling on a turbine blade,this paper is composed of three parts.First the impingement-convection cooling on th internal surface of a blade leading edge is investigated,in result an empirical expression of internal-local heat transfer coefficients at the stagnation point is formulated and regularity of their variatons along the leading edge region is found.Secondly,the variations of the film-cooling effectiveness along the external surface of the leading edge are investigated according to various blowing ratios when the film jets ejected from the film holes on the blade.Thirdly,as the film jets impose some disturbances on the main stream,heat transfer is enhanced,as a result a set of empirical expressions for the external-local heat transfer coefficients are formulated.