Uncertainty quantification for the trailing-edge noise of a controlled-diffusion airfoil

A study that examine uncertainties associated with the prediction of trailing-edge noise, through an uncertainty quantification (UQ) framework, using RANS computations or conventional LES computations, in order to determine their respective robustness and accuracy is presented. The uncertainty is introduced at the inlet boundary of the restricted computational domain. The physical variations in the experimental flow measurements are taken into account by selecting a 2.5% error bound on the streamwise velocity U and a 10% error bound on the crosswise velocity V around the deterministic numerical solution. This observation is a significant departure from RANS computations where the second recirculation zone beyond mid-chord never occurs for low aoa. This difference is related to the used RANS modelisation that is considering fully turbulent flows and therefore cannot correctly take into account the laminar and transition regions whereas LES calculations do.