Low-Fidelity Stochastic Approach for Airfoil-Turbulence Interaction Noise
* Presenting author
The noise due to the interaction of turbulent flow with the leading edge an airfoil is the main source of aerodynamic noise. Turbulence is, by its very nature, stochastic and therefore has a broad frequency spectrum which makes it more difficult to calculate the effect induced by it. Acoustic radiation from an airfoil subjected to a real flow is one such effect induced by turbulence and demands high-performance computing for its prediction numerically. The methods which are available now range back from analytical ones, which are fast but not precise enough to capture nonlinear effects, to the numerical one, which heavily depends on the computing power. A new approach to model the noise from turbulent flows is presented to bridge the low fidelity and high-fidelity methods. The pressure fluctuations over the body immersed in the turbulent flow field are calculated using the BEM with Neumann boundary condition and unsteady Kutta-condition. The unsteadiness in the domain is induced by allowing the free flow of vortices through it. The pressure signals are then used to calculate the sound radiation using Ffowcs-Williams and Hawkings analogy. The approach has been validated against analytical solutions of the linearized wave equations and experimental data available.