Vibration response of fluid-loaded structures to low-speed flow noise

Abstract

Consider a spatially homogeneous and temporally stationary random pressure field exciting a spatially homogeneous structure. It is well known that when the power exchange between the pressure field and the structure results from a ’’surface interaction’’ rather than from a scattering-induced ’’edge interaction,’’ it is immaterial whether a finite or infinitely extended model of the structure is used to calculate this power exchange. This equivalence is discussed and used to estimate vibration response of fluid-loaded structures when excited by a low-speed turbulent boundary-layer flow. Connections, established previously for structures in vacuo, between group velocity, modal density, and point and line conductances, are also generalized to apply to fluid-loaded structures. Finally, an approximate but simple method is suggested for estimating vibration characteristics of spatially nonhomogeneous structures excited by surface interactions.