Monte-carlo computation of wall-pressure spectra under turbulent boundary layers for trailing-edge noise prediction

International audienceThe quantification of the spectrum of wall-pressure fluctuations under a turbulent boundary layer has a fundamental role in problems of aerodynamic noise generation and structural vibration. Advanced analytic formulations of the wall-pressure spectrum involve multi-dimensional integrals. The computation of these integral formulations with quadrature methods proves computationally expensive, especially if many flow configurations are taken into account. For this reason, Monte-Carlo methods are used to distribute a predefined number of samples of the integrand function in the integration space and obtain a rapid and accurate estimate of the integral value. This work reviews the expression of the wall-pressure spectrum based on the Poisson equation for pressure fluctuations in a turbulent field and then applies three different Monte-Carlo methods to its computation: the quasi-uniform sampling, the recursive stratified sampling and the importance sampling. The criteria for the choice of the most appropriate Monte-Carlo method are finally discussed