Experimental Study on BTI Broadband Noise Reduction with Wavy Leading Edge for Sweep Blade
* Presenting author
Experimental studies are performed to investigate the Blade-Turbulence Interaction (BTI) noise reduction of a sweep blade using wavy leading edge(WLE) configuration. The noise radiation from the blade is generated by the interaction of blade and incoming anisotropic turbulence which is produced by a rod whose wake impinges onto the downstream blade. The BTI noise of the blade with swept angle of 30 degrees and constructed by NACA0012 airfoil with and without wavy leading edge were measured with the flow speeds of 30m/s to 70m/s. A linear array of 31 microphones was used to determine the BTI noise. The 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 in order 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 Strouhal number is almost the same for same WLE under different airflow velocities.