DDES Study on the Influence of a Whisker Trailing Edge on the Wake-Blade Interaction of a High-Pressure Turbine Stage

Abstract

In this study, the whisker structure of a harbor seal is utilized on the trailing edge of a high-pressure turbine stage to control the interaction between the wake and the blade. The paper investigates two cases: a prototype high-pressure turbine stage, and a biomimetic turbine stage where the vane and blade trailing edges are modified to mimic the whisker structure. The flow in the prototype and the biomimetic turbine stage is simulated using the delayed detached-eddy simulation (DDES) method. Results show that fluid behind the whisker trailing edge converges to the valley region. The whisker trailing edge transforms the Karman vortices into hairpin vortices, narrowing the wake area of the vane. A narrower wake area delays the interaction between the wake core area and the blade. The prototype vane’s pressure-side and suction-side shedding vortices interact with the leading edge of the blade, resulting in large pressure fluctuations. The whisker trailing edge weakens the impact of the wake on the blade’s leading edge, significantly reducing the amplitude of pressure fluctuation at the blade’s leading edge. Meanwhile, the whisker trailing edge minimizes the adhesion of the small vortices on the blade, suppressing the high-frequency pressure pulsation at the blade’s leading edge. Moreover, the breaking of the Karman vortex suppresses the rotational velocity field in the blade passage. The suppression of the rotational velocity field of the shedding vortex reduces the velocity fluctuations in the blade’s near-wall region and boundary layer.