稀疏气膜冷气侧局部换热特性实验

涡轮叶片弦中区的冷却为冲击带初始横流和气膜孔溢流的复杂流动换热,通过实验的方法,研究了涡轮叶片弦中区沿流向局部换热特性和靶板平均换热特性随冲击雷诺数、横流射流密流比、气膜出流与横流密流比以及冲击腔高度与冲击孔直径之比的变化规律,并通过气膜出流与横流密流比对局部换热效果、区域平均换热效果以及靶板整体平均换热效果的影响规律揭示气膜的介人对冷气侧换热带来的影响.

Interior local heat transfer!characteristics of midchord region due to sparse film cooling holes

The cooling flow and heat transfer in the midchord region of turbine blade are very complex as a result of the reciprocity among the impinging jet,initial cross-flow and outflow from film cooling holes.Experiments are carried out in order to acquire the local and average heat transfer characteristics for various impinging Reynolds numbers,density flow ratios of film outflow to initial cross flow,density flow ratios of initial cross flow to impinging jet flow and impinging distance to impinging jet hole diameter when complex flows exist.Moreover,the variations of local Nusselt number and average Nusselt number characteristics in the whole target surface and different regions of that have been discussed so as to disclose the incidence of the sparse film holes to the interior heat transfer in the midchord of turbine blade.