Numerical Study of Leakage Flow Characteristics by Tip Clearance of Turbine Cascades

터빈익렬 말단간극에 따른 누설유동특성에 대한 수치해석적 연구

Numerical analysis has been conducted in order to simulate the flow characteristics by tip clearance of turbine cascades. A 3-D Navier-Stokes CFD code based on body-fitted coordinate system, pressure-correction and finite volume method has been used along with a commercial CFD code. The present results have showed that the development and generation of leakage vortex, vortex within tip clearance, etc. are clearly simulated, consistent with the generally known tendency. The leakage vortex occurs mainly by a separation of leakage flow that arises due to a pressure difference between two surfaces of the blade at the tip.