Aeroacoustic Numerical Investigation of a Scaled Compressor Cascade

Abstract

In order to further develop technologies to reduce noise emissions of aero engines, an understanding of the noise propagation through compressor blade rows of modern turbofan engines is of major importance. To enable more detailed experimental investigations of the sound propagation in aero engines, engine components or stages have to be scaled for an installation into test rigs that allow for experiments under acoustically optimized boundary conditions. The main focus of the present work is thus to discuss a scaling approach that ensures both aerodynamic and aeroacoustic similarity between a given test rig and engine. For that purpose, a stator row of a four-stage high-speed axial compressor (4AC) based on the test rig at the Institute of Turbomachinery and Fluid Dynamics (TFD) at the Leibniz University Hanover is scaled to fit into the TFD's Aeroacoustic Wind Tunnel (AWT). Numerical investigations based on multiple modeling approaches are performed to verify a similar aeroacoustic behaviour in both test rigs. Reynolds-Averaged Navier-Stokes (RANS) and Unsteady-RANS simulations are carried out to assess the aerodynamic characteristics of the blade rows. The aeroacoustic modelling consists of simulations with an Euler acoustic solver to compare the modal transmis-1 The presented work was divided equally between the Institute of Turbomachinery and Fluid Dynamics in Hanover and the Mechanical Engineering Department in Sherbrooke