LES Study on the Mechanism of Wake Vortex Shedding in Transonic Turbine

This work employs a high-resolution large eddy simulation (LES) to reveal the unsteady flow characteristics of transonic turbine cascades. The results show that a distinct dovetail-shaped shock wave structure forms at the trailing edge of the cascade. PS-TE-shock impingement on the adjacent suction surface triggers boundary layer separation and rapid transition to turbulence. Wake shedding originates from shear-driven vortices forming at the trailing-edge shock intersection and detaching periodically. Pressure waves generated during shedding prop agate downstream along the PS-TE-shock, impacting the suction surface boundary layer and influencing its flow. POD analysis further elucidates the pressure wave propagation path.