Sound power radiation due to an isolated airfoil in a turbulent stream

This paper presents an analytical study of the sound power radiated from a two dimensional flat plate airfoil in a turbulent stream. A classical approach for describing analytically the response of a flat plate, with a finite chord, to th e impingement of turbulence is extended to be valid at all frequencies. Analytical asymptotic expressions, valid at low and high frequencies, are provided for the upstream, downstream and total sound power. A study of the effects of chord length on the total sound power at all reduced frequencies is presented. The isolated airfoil model presented in this paper will subsequently be used as a benchmark to study the effects of cascade in broadband interaction noise of fans.