Abstract: The turbulent flow through an axial compressor cascade and the sound induced by the flow are computed based on a large eddy simulation(LES) model and the boundary element method. The influence of the freestream angle of attack and Reynolds number on sound generation and radiation in the cascade at different stagger angles are analyzed. The results indicate that the total sound pressure level first decreases, then increases when the stagger angle and Reynolds number are constant while the angle of attack changes from -5? to 20?. The minimum sound pressure level appears at the angle of attack of 0?. At stagger angle of 45?, the total sound pressure level of the cascade changes varying with angle of attack, the trend is similar to that of the stagger angle of 30?. However, at the stagger angle of 60?, the total sound pressure level changes more gently. At the angle of attack of 0?, the sound pressure level increases about 6 dB comparing with the case of the stagger angle of 30癮nd 45?. At other positive angles of attack, the changes are not obvious. The minimum sound pressure level appears at the direction of the cascade chord. The positions of the minimum sound pressure level vary with change of stagger angles. With a constant stagger angle, surface separation and flow loss decrease with the increase of the Reynolds number. However, the surface pressure fluctuation of cascade and the far-field radiation sound increase.

Key words: compressor cascade, stagger angle, freestream angle of attack, freestream Reynolds number, large eddy simulation, aerodynamic sound