Experimental Study on the Effects of Upstream Periodic Wakes on Cascade with Tip Clearance

주기적 후류가 누설유동이 존재하는 익렬 유동에 미치는 영향에 대한 실험적 연구

To research on change of blade row flow field with tip clearance caused by upstream periodic wake, an apparatus that generate periodic wake through traversing cylinders were installed. Then how movement of upstream wake affect cascade flow and tip leakage flow were measured. Cylinder was installed in front of 50% of chord length, and traversing velocity was calculated at approximately 11.7m/s regarding inlet velocity and chord length. To measure three-dimensional velocity of flow inside blade row, single slanted hot-wire was used. From the results, when the periodic wake is inserted, the flow inside of cascade is dominantly affected by vortex that is generated from cylinder. This periodic wake affects passage vortex and tip leakage vortex.