On the flow and noise of a two-dimensional step element in a turbulent boundary layer

Abstract

This paper presents results of a study on the flow and noise generated by two-dimensional step elements attached to a flat plate. The step elements used in this study are equivalent to a forward-backward facing step pair and have length to height ratio of l/h = 8, 4 and 2.7. Aerodynamic and acoustic measurements have been taken in an anechoic wind tunnel at the University of Adelaide. Numerical simulations of turbulent boundary layer flow over the step with l/h = 2.7 are also presented. The data given in this paper provide fundamental information on how a sub-boundary layer step element affects the noise and flow field.