Trailing Edge Noise Prediction Based on a New Acoustic Formulation

A new analytic result in acoustics called "Formula-tion 1B," proposed by Farassat, is used to computebroadband trailing edge noise from an unsteady surfacepressure distribution on a thin airfoil in the time do-main. This formulation is a new solution of the FfowcsWilliams-Hawkings equation with the loading sourceterm, and has been shown in previous research to pro-vide time domain predictions of broadband noise that arein excellent agreement with experiment. Furthermore,this formulation lends itself readily to rotating referenceflames and statistical analysis of broadband trailing edgenoise. Formulation 1B is used to calculate the fax-fieldnoise radiated from the trailing edge of a NACA 0012airfoil in low Mach number flows, using both analyti-cal and experimental data on the airfoil surface. Theresults are compared to analytical results and experi-mental measurements that are available in the literature.Good agreement between predictions and measurementsis obtained.Nomenclaturegk_