Numerical Calculation of Aerodynamic Noise Generated from an Aircraft in Low Mach Number Flight

Abstract

The paper describes numerical prediction of aerodynamic noise generated from the aircraft. It focuses on the simulation of turbulent flow around rectified flap on the wing represented in 2D. Simulation of turbulent flow is modeled using the stabilized orthogonal subgrid scale (OSGS) method with dynamical subscales. It is shown how the stabilization method can perform simulation of turbulent flow affecting the prediction of acoustic sources calculated applying Lighthill’s analogy. Acoustic sources are used in inhomogeneous Helmholtz equation to simulate pressure wave propagation in the domain closing the circle of three main steps required for simulating aeroacoustics phenomena. It is shown that OSGS with dynamical subscales gives better representation of the spectrum. Overall, better prediction of energy transfer across large and small eddies provides better allocation and presentation of acoustics sources. These sources change wave propagation of the pressure in acoustic field.