Large-Eddy Simulation of a Linear Compressor Cascade with Tip Flow: Effects of the Moving Endwall on the Aerodynamics

Abstract

A wall-resolved compressible Large-Eddy Simulation of a linear compressor cascade with a moving end-wall has been performed with the high-order unstructured solver AVBP in order to study the effects of the wall motion on the tip-leakage flow aerodynamics. The cascade is composed of eight controlled diffusion airfoils with a tip-gap of 1.6% chord and a pitch-to-chord ratio of 0.925. The inflow Mach number is 0.07 and the Reynolds number based on the chord is 3:88 106. The moving end-wall moves in the pitchwise direction with a velocity magnitude that is 90.8% of the freestream inflow velocity. The main fluid-dynamic structures as the Tip-Leakage Vortex (TLV) and the wake have been resolved. Finally, a comparison between the current case and a previous simulation with a stationary end-wall has been done in order to investigate the effects of the wall motion in details. The TLV is flattened and entrained by the wall motion, resulting in a modified trajectory of the vortex. Moreover, this is characterized by lower turbulent kinetic energy. The aerodynamic comparison between the two cases sets the stage for a consistent aeroacoustic analysis.