Fast Non-empiric Propeller Source Noise Model with Mean Flow

A fast and physical-principles-based method to compute the noise radiation for installed propellers’ applications is introduced. The simulation of the sound propagation includes newly defined perturbation equations, with propeller sound sources modelled as rotating singularities. The system of equations proposed is derived from the Linearised Euler Equations, after the application of a split-approach on the velocity perturbations. Two separate coupled systems of equations are obtained, the Acoustic Perturbation Equations, governing the acoustic velocity and pressure perturbations, and the Vortical Convection Equations, describing the convection of non-acoustic velocity perturbations. The moving sources are regularised with a Gaussian kernel over the computational mesh, allowing their description within an unstructured quadrature-free Discontinuous Galerkin experimental solver for Computational Aeroacoustics applications. The prediction capabilities of the method proposed have been successfully validated with a simple test case.