Extension of the Amiet theory for compact leading edge airfoil noise prediction

The Amiet theory is a semi-analytical methodology able to compute the airfoil noise, which is specially applicable to frequencies where the airfoil chord is comparable, or smaller, than the gust hydrodynamic wavelength and, consequently, the airfoil can be considered as a non-compact noise source. For lower frequencies, where the gust wavelength is comparable, or larger, than the airfoil chord, the Amiet theory overpredicts the airfoil noise. This paper discusses the effects of approximations made to the analytical methodology showing that they are partially responsible for the noise superestimation and proposes an iterative procedure of leading and trailing edge correction in order to improve the agreement of this theory with experimental data.