Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
654984 | International Journal of Heat and Fluid Flow | 2015 | 11 Pages |
Abstract
The effect of winglet width-to-pitch ratio, w/p, on tip leakage aerodynamics over the cavity squealer tip equipped with full coverage (FC) winglets for a squealer rim height-to-span ratio of hst/s = 3.75% has been investigated in a turbine cascade for a tip gap-to-span ratio of h/s = 1.36%. Based on near-tip flow visualizations and flow measurements, various tip leakage flow changes by installing the FC winglet on the cavity squealer tip are discussed in detail. With the increment of w/p, the total pressure loss coefficient mass-averaged all over the measurement plane, Câ¾Pt, for the cavity squealer tip with the FC winglet increases for w/p ⩽ 2.64%, decreases for 2.64% < w/p < 10.55%, and then becomes nearly constant. The maximum reduction of Câ¾Pt by installing the FC winglet on the cavity squealer tip is 5.8% of Câ¾Pt for the cavity squealer tip without winglet. This is only almost half of the maximum loss reduction by installing the FC winglet on the plane tip with respect to Câ¾Pt for the plane tip without winglet. As w/p increases, the FC winglet works better in flow turning within the turbine blade passage.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Fluid Flow and Transfer Processes
Authors
Joo Hong Cheon, Sang Woo Lee,