LAUSR

Abstract The suction side film cooling performance of a rotating blade is investigated numerically and experimentally in this paper. Three types of tip structures, including flat tip, double squealer tip and single squealer tip, are chosen to generate different leakage vortexes and study the tip leakage effects. The experiments were established in the rotating turbine film cooling facility of Beihang University. In the experiments, the hole position moves from 5/8 to 7/8 of the total blade height, and the effect of hole position was investigated. At last, the rotating Reynolds number changes from 4036 to 6954 and then to 9623. The rotation effects are also investigated. In the numerical simulation, a k-e model is used, and the results were validated by comparing them with the experimental data. The numerical simulation results show that the film flow is severely influenced by the passage vortex and the leakage vortex. For the double squealer tip results, the leakage flow attaches well. Moreover, the leakage vortex and the passage vortex decrease from the blade tip to the mid-span. At last, the rotation strengthens the passage vortex and weakens the leakage vortex. As a result, the film deflection increases from 5° to 12° in the experiments. Additionally, the film coverage decreases. Regarding the tip structure effects, the double squealer tip proved to achieve the best film performance, while the single squealer tip can help to resist the film deflection.