Noise from interaction of flow with rigid surfaces: A review of current status of prediction techniques

A brief review of some fundamental aspects of sound arising from turbulent boundary layers, noise due to flow past a single discontinuity (trailing edge), noise from airfoils operating in turbulent flow, and noise due to rigid flow discontinuities (spoilers) immersed in rigid ducts is presented. Emphasis is on dipole-like sound fields associated with turbulent flow past a trailing edge, rigid bodies in turbulence and in-duct spoilers. Representative available data are reviewed and evaluated in terms of theoretical considerations and, where possible, empirical prediction techniques are given in terms of convenient aerodynamic and geometric parameters. Limitations on current knowledge are discussed.