Investigation Of Flow Resistance And Heat Transfer In The Internal Cooling Passage With Ribs And Film Holes

Film cooling and force convective heat transfer are widely used for the turbine blade. Influence of flow and geometry on the heat transfer coefficients of the surfaces need to be studied carefully. The detailed knowledge of the heat transfer enhancement and flow is required to optimize cooling design. This thesis describes the experimental and numerical researches of the heat transfer and flow.Discharge coefficients and pressure distribution are measured at the case of Reynolds number from 60000 to 150000, take-off ratios of 0.04 to 0.22. Heat transfer coefficients are measured by applying transient liquid crystal technique with the varying Reynolds number from 30000 to 90000, suction ratios 0.09-0.22. Rib turbulator angles vary from 60° to 120° . Rib turbulators are located on the upstream, downstream and middle of the film cooling holes. The results show that discharge coefficients are mainly controlled by hole Reynolds number. Pressure coefficients increase with increasing Reynolds and take-off ratios. Geometries have little impact on the average heat transfer coefficients but large influences on the local heat transfer coefficients.Numerical investigation is conducted with the same case of the experiment and the results agree well with the experimental data. Heat transfer coefficients of no film holes surfaces and the influences of rotation on the discharge coefficients are investigated. The numerical results show that the heat transfer coefficients of the four surfaces in the internal passage are very different and the max heat transfer coefficient occurs at the one of the smooth surface. Rotations have large influence on the discharge coefficients of the film cooling holes.