Bluff Body Noise Reduction Using Aerodynamic Interference

Abstract This paper will discuss a method of bluff body noise control that utilises the phenomenon of aerodynamic interference. This technique uses a second body (not necessarily bluff) that is placed in the wake of the bluff body whose noise we wish to control. Through proper understanding of the wake dynamics, the amplitude and phase of the noise from the downstream body can be controlled so as to achieve noise reduction in the far-field. This paper will present a theoretical model of noise reduction via aerodynamic interference based on the theory of Curle. The noise from a two-dimensional square cylinder will be then assessed numerically with and without a flat plate placed within its wake. The results show that the presence of the downstream body creates a high level of non-linear interference that needs to be understood in detail before effective noise reduction can occur.