Effects of rotating on the discharge coefficients of film holes in turbine blade

The effects of the rotation on the discharge coefficient were studied. Numerical simulation was conducted to investigate discharge coefficients of film holes in rectangular channel with both rib-roughened wall and film hole suctions at Reynolds number Re = 60000, 150000, rotation number 0, 0.11, 0.22, suction ratio of 0.09 and 0.22. A finite volume method with unstructured meshes was used to solve the three dimensional compressible Navier-Stokes equations. The standard k-ε model was used and the standard wall function was utilized for near wall treatment. The numerical results agreed well with the experimental data of the stationary passages. Investigation was focused on the effects of rotation number on the discharge coefficients of the film holes. The results showed that the discharge coefficients increased when the channel rotated clockwise and decreased when the channel rotated counter clockwise. It also showed that the discharge coefficients of the two film holes at the same radial position were different. The discharge coefficients of the left holes were higher than those of the right holes when the channel rotated clockwise while the discharge coefficients of the left holes were lower than those of the right holes when the channel rotated counter clockwise.