PREDICTION OF FLOW-INDUCED STRUCTURAL VIBRATION AND SOUND RADIATION USING ENERGY FLOW ANALYSIS

Abstract The energy flow analysis method used to predict the structural vibration response and the radiated sound power of a plate excited by wall pressure fluctuations under turbulent boundary layers, and separated-reattached flows. This method allows the spatially averages energy density and response to be calculated for non-uniform, distributed excitations while taking hydrodynamic flow/structural coupling effects into consideration. The power input was calculated using well known analytical models for the plate mechanical impedance and empirical models for the surface pressure cross-power spectral density and/or wave number-frequency spectral density. The Smol'yakov-Tkachenko model was used to estimate the fluctuation pressure field underneath turbulent boundary layer flows. The Corcos model was used to estimate the wall pressure field under non-uniform, separated-reattached flows. Experiments were performed in order to evaluate the energy flow model. A clamped plate installed in a quiet, low-speed wind tunnel was used. The wall pressure fluctuations, the plate vibration response, and the acoustic pressure radiated from the plate were measured. The energy flow analysis method was found to provide reasonably accurate predictions of the frequency-averaged transverse velocity response of the plate at high frequencies. The acoustic pressure radiated on the quiescent side of the plate was also predicted with comparable accuracy.