Analytical and experimental investigation into the effects of leading-edge radius on gust-aerofoil interaction noise
Journal of Fluid Mechanics
Cambridge University Press
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Ayton, L., & Chaitanya, P. (2017). Analytical and experimental investigation into the effects of leading-edge radius on gust-aerofoil interaction noise. Journal of Fluid Mechanics, 829 780-808. https://doi.org/10.1017/jfm.2017.594
This paper investigates the effects of local leading-edge geometry on unsteady aerofoil interaction noise. Analytical results are obtained by extending previous work for parabolic leading edges to leading edges of the form for . Rapid distortion theory governs the interaction of an unsteady vortical perturbation with a rigid aerofoil in compressible steady mean flow that is uniform far upstream. For high-frequency gusts interacting with aerofoils of small total thickness this allows a matched asymptotic solution to be obtained. This paper mainly focusses on obtaining the analytic solution in the leading-edge inner region, which is the dominant term in determining the total far-field acoustic directivity, and contains the effects of the local leading-edge geometry. Experimental measurements for the noise generated by aerofoils with different leading-edge nose radii in uniform flow with approximate homogeneous, isotropic turbulence are also presented. Both experimental and analytic results predict that a larger nose radius generates less overall noise in low-Mach-number flow. By considering individual terms in the analytic solution, this paper is able to propose reasons behind this result.
LA is grateful to Sidney Sussex College for providing financial support.
External DOI: https://doi.org/10.1017/jfm.2017.594
This record's URL: https://www.repository.cam.ac.uk/handle/1810/270044