Validation of hybrid method for fan tonal noise radiation

An integrated computational approach, containing nonlinear harmonic (NLH) method and boundary integral equation method (BIEM), is developed for the prediction of fan tonal noise. The NLH method is used for the computation of acoustic sources, and the BIEM is for acoustic prediction module. The sound propagation in the cylindrical duct and sound radiation outside the duct can be predicted simultaneously. Then, the approach is applied to tonal noise prediction of the Advanced Noise Control Fan (ANCF) developed by NASA Glenn Research Center. The far field acoustic results of the present method are compared with the experimental measurements and numerical simulations. The accuracy of comparison emphasizes that the present method is general and efficient for the prediction of fan tonal noise. Three mesh solutions and 2 different turbulence models are compared. Then, discussions of aerodynamic and aeroacoustic results in 3 different operating conditions are demonstrated.