A Parametric Investigation of Wake Loss Reduction by using Serrated Trailing Edge in a High-speed Compressor Cascade

Abstract

The influence of the serration with different widths, angles and spanwise locations on the wake of a high-speed compressor cascade is parametrically investigated by numerical simulation. The effect mechanisms of the serration on the cascade performance are discussed in detail and the potential at the off-design points is also validated. The results show that the momentum inputted by the serration jet and the fluid exchange induced by the dominant jet vortex could reenergize the low energy corner region and weaken the trailing edge shedding vortex. With the upstream shift of the serration valley, the loss reduction and pressure rise are enhanced due to the strengthened jet and counter-rotating vortex pair, whereas the flow turning is reduced by the decreased camber angle and the enhanced jet deflection. The serration at the blade height corresponding to the core of the low energy fluid could perform better for the loss reduction, whereas the serration close to the endwall could obtain higher pressure rise. For the optimal serration located at 12.5 % blade height with a width of 5 mm and an angle of 45 °, the loss is reduced by 8.9 % and the pressure rise is increased by 2.2 %, with the flow turning slightly reduced by 0.93 °