Aerodynamic noise prediction of the 1.5-stage axial compressor of a gas turbine

Abstract

Aiming at the complexity of the aerodynamic sound source of the multi-row blade rotating machinery, we developed a numerical simulation method for the aerodynamic noise of a multi-row impeller. The aerodynamic noise characteristics of the 1.5-stage compressor of the gas turbine were studied based on the hybrid calculation method. The shear stress transport turbulence model was used to calculate the three-dimensional unsteady flow field of the 1.5-stage axial compressor, obtaining the sound source. Then, the compressor noise was predicted based on the Lighthill acoustic analogy coupling sound source information in the variational form, and experimental research on the flow field and noise was performed on the compressor dynamic test bench. The results show that the unsteady pressure pulsation peak after a Fourier transform mainly appeared at the blade pass frequency and its harmonics, and the pressure amplitude decreased with the increase in the blade frequency order. The forward noise had obvious acoustic directivity and dipole characteristics, and discrete noise contained high-order modes that can be propagated. The numerical simulation results are in good agreement with the experimental results. The numerical calculation method developed in this work has high accuracy in predicting the aerodynamic noise of multi-row impellers.