Estimation of broadband acoustic power due to rib forces on a reinforced panel under turbulent boundary layer-like pressure excitation. I. Derivations using string model.

Abstract

This paper shows that, when the attachment forces on a rib-reinforced panel subjected to turbulent boundary layer (TBL) excitation can be considered to radiate independently, the rib-related acoustic power in a broad (e.g., one-third octave) frequency band can be estimated as the product of the average mean-squared force, the real part of the radiation admittance of an attachment force, and the number of ribs. Using a simple model of a string with point mass or spring attachments, an approach is developed for estimating the average mean-squared force in broad frequency bands. The results are in a form that can be applied to ribbed plates and shells. The following paper establishes the condition under which the ribs can be considered to radiate independently, and presents the results of validating calculations for steel plates in water.