Experimental Study on BTI Broadband Noise Reduction with Wavy Leading Edge for Sweep Blade

摘要

Experimental studies are performed to investigate the Blade-Turbulence Interaction (BTI) noise reduction of a sweep blade with wavy leading-edge (WLE) configuration. The noise radiation from the sweep blade leading-edge is generated by the interaction of the blade and incoming anisotropic turbulence which is produced by a rod whose wake impinges onto the downstream NACA0012 airfoil. A linear array of 31 microphones was used in this study to determine the BTI noise source. With the Clean-SC approach, clear and quantitative sound radiation results of the leading-edge noise source of swept blade are obtained. Parametric studies of the WLE amplitude and wavelength are conducted to understand the effect of WLE on BTI noise reduction. It is observed that the OASPL reduction is sensitive to both the amplitude and wavelength of the WLE. The WLE with the largest amplitude and smallest wavelength can achieve the most considerable OASPL reduction up to 2dB. It is found in this study that the spectra of BTI noise reduction with Strauhal number is almost the same for same WLE under different airflow velocities.