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Project supervisor and contact Zhang, Xin ([email protected] ) Swire Professor of Aerospace Engineering, Chair Professor Department of Mechanical and Aerospace Engineering Aerodynamics Acoustics & Noise Control Technology Centre aantc.ust.hk Sliding grid simulation of cascade noise Wei Ying and Ryu Fattah Effect of advance ratio J on PWL The wake rotation speed has no significant effect on the noise generated by the cascade, due to the similar levels of averaged turbulence intensity across each case. This will remain true, as long as the separation between adjacent wakes is a constant. Aim The rotational motion of the fan blades was considered, by applying a high-order hybrid sliding interface between the turbulence injection region and the OGVs. The effect of the advance ratio and turbulence properties of the fan- wakes, such as the wake width and turbulent integral length scale, on the sound power level, were investigated. The sound power level obtained are compared to analytical predictions. Acknowledgements Ying Wei is supported by a PhD fellowship. This study is supported by Hong Kong Research Grant Council (RGC) grants [projects 16204316 and 16203817]. Background Turbofan engines are commonly used on modern commercial aircrafts and have become a significant source of noise pollution. The tonal noise generated by turbofan engines has been extensively studied, and noise reduction approaches such as acoustic liners have been developed. The dominant source of broadband noise is due to the turbulent fan-wake interacting with the leading edges of the outlet guide vanes (OGV). Upstream PWL Downstream PWL Vorticity magnitude (J=1.25) Instantaneous p’ (J=1.25)
