Analytical Representations of Fluid-Structure Interaction Noise Predicted From Large Simulations
Abstract
Approximations are derived for the three-dimensional Green's function for an airfoil of finite thickness and chord for sources near the leading or trailing edge. The acoustic wavelength is large relative to the airfoil thickness, but no restriction is placed on its magnitude relative to the chord. Extension is made to production of sound by flow over the trailing edge of an airfoil with a single detached flap. Green's function is derived for a detached flap at relative angle of attack a when the chord of the flap is acoustically compact. Formulae are given for calculating the 'self-noise' produced by boundary layer instability; the efficiency of sound generation at the edge of the airfoil is shown to be typically at least 7 dB larger than that produced at the trailing edge of the flap. The results can be incorporated into a numerical scheme for predicting airfoil noise at low Mach numbers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 27, 2000
- Accession Number
- ADA375900
Entities
People
- M. S. Howe
Organizations
- Boston University