Trailing-edge noise prediction using synthetic turbulence and acoustic perturbation equations in a hybrid methodology

https://arc.aiaa.org/doi/10.2514/6.2017-3846In this work a hybrid RANS/CAA methodology is used to predict trailing-edge noise of a controlled-diffusion airfoil. A time domain stochastic solver based on the Random Particle Mesh method introduced by Ewert et al. is used to generate turbulent fluctuations in 2-D that accurately reproduce statistical and mean-flow features provided by steady RANS. Acoustic Perturbation Equations coupled with the stochastic solver are solved in time domain, using a vortex sound source term defined in terms of stochastically generated turbulent velocity fluctuations. The far-field sound pressure level obtained using Kirchhoff extrapolation method followed by 2-D to 3-D correction taking into account the finite span of the airfoil is compared with the available experimental data. The numerical results are found to be in good agreement for the frequencies for which experimental data is available. The results indicate the suitability of the 2-D RANS/CAA approach for trailing-edge noise prediction from airfoils with uniform cross-section in the spanwise direction.status: publishe