On the mechanisms of noise reduction in aerofoil-turbulence interaction by using wavy leading edges

A novel aerofoil leading-edge profile based on wavy (sinusoidal) protuberances/tubercles is investigated numerically to understand its effectiveness for the reduction of aerofoilturbulence interaction noise. Non-lifting flat-plate aerofoils with straight and wavy leading edges (denoted by SLE and WLE, respectively) are employed and subjected to an impinging turbulence that is synthetically generated in the upstream zone. A full three-dimensional Euler (inviscid) simulations are performed for this study in order to avoid developing selfnoise due to viscosity. The free-stream Mach number is set to 0.24. A high-order accurate finite-difference based solver and artefact-free boundary conditions are used in the current simulations. Various frequency-spectra and statistical analysis are implemented in order to investigate and understand the noise reduction mechanisms.

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