Vibration and Noise Generation by Elastic Elements Excited by a Turbulent Flow

A Wavenumber Approach to Modelling the Response of a Randomly Excited Panel, Part I: General Theory

“…Such expressions have already been used in similar studies [10,13]. However, for the sake of completeness, we will describe the main steps of the proof.…”

“…Equation (25) is a classical expression that has been used by many authors to evaluate the response of a #uid-loaded plate to a turbulent wall-pressure [23, 24, 27}31]. However, recent advances in the modelling of turbulence have provided expressions for the wall-pressure #uctuations given in the form of a wavevector}frequency power spectrum [7,14] and an increasing number of studies are now considering formulations in the wavenumber}frequency domain [11,13,32,33].…”

“…is the angular frequency and k $ is the acoustic wavenumber in each #uid domain. In equation (13), if we assume that the mechanical damping is hysteretic, then ( ) is given b sign( )/ where is the hysteretic loss factor and L . "L .…”

“…However, the accuracy of the numerical approximations used to determine the sensitivity function for "nite and complex structures relies on the validity of the simplifying assumptions for the model, and also, on the quality of the approximation method (convergence, consistence, etc). Several studies have already considered the in#uence of a turbulent excitation model on the system response [13,14].…”

Experimental Study of Noise Produced by Steady Flow Through a Simulated Vascular Stenosis

“…In the frameworks of the acoustic models developed by these authors, relationships between the spectral and correlation characteristics of the acoustic "eld heard at the body surface and the parameters of the vessel and the turbulent #ow were derived, and the transfer function of the thorax was obtained. Using available low-Mach number turbulent wall pressure models [17,18], the changes in the acoustic "eld due to changes in the parameters of vessel and mean #ow were found. In particular, the noise level was shown in references [23,24] to increase as the vessel diameter decreases and/or the mean #ow velocity increases.…”