Experimental Study Of Film Cooling Of Turbine Blade Surface

A series of research on the turbine stator blade were made in this paper. The turbine cascade test sections and turbine blades were set up according to the geometry provided by Gas Turbine Establishment of China. There are two experiment blades. The blade with smooth surface is used for pressure investigate, and another blade has 18 rows cylindric filmcooing holes on the surface. Experimental measurements were carried out in a large-scale low speed heat transfer wind tunnel in Northwestern Poly-technical University.Firstly, the pressure coefficients and the velocity ratios distribution on the stator blade surface were measured with the Reynolds number of Re_∞ = 50,000 ~ 270,000. The influence of mainstream Reynolds numbers on the pressure coefficients and the velocity ratios were investigated. Then, the discharge coefficients of film holes were obtained in the condition of Re_∞ = 50,000 ~ 270,000 , BR = 0.5 ~ 2.0 for stator. The influence of Reynolds numbers and blowing ratios on discharge coefficients were investigated. The results have shown that the blowing ratios are the main influence on the discharge coefficients of film holes. Thirdly, the local heat transfer coefficients and the film cooling effectiveness at different locations on blade surface were detailed measured in the cases of mainstream Reynolds number changing from 50000 to 270000 and blowing ratio changing from 0.5 to 2.0. The influence of Reynolds numbers and blowing ratios on local heat transfer coefficients and the film cooling effectiveness on blade surface were investigated. Lastly, when the secondary flow was CO, and the filmcooling holes were all opened, the local heat transfer coefficients on the blade surface were measured . and the influence of the density ratios on the local heat transfer coefficients were investigated.The results have shown that the influence of the mainstream Reynolds numbers on the film hole discharge coefficients and the film cooling effectiveness on blade surface were less, but the influence of the mainstream Reynolds numbers on the local heat transfer coefficients on blade surface were obviously. Film hole discharge coefficients were increased obviously with blowing ratio. And the influence of blowing ratio on the film cooling effectiveness and the local heat transfer coefficients on blade surface were complex, the local heat transfer coefficients on blade surface were influenced by density ratios, and the influence was complex.