The characteristics and mechanisms of turbulent pressure induced self-noise of the elastomer layer attached stiffened plate

In order to study the characteristics and mechanisms of turbulent pressure induced self-noise of the elastomer layer attached stiffened plate,the elastomer layer attached periodically stiffened plate model induced by turbulent fluctuating pressure was established based on turbulent wall pressure fluctuation spectrum model,periodically stiffened plate flexural motion equation,three-dimensional solid wave equation as well as force equilibrium and displacement continuity conditions.The study indicates:the noise reduction of self-noise of the turbulent induced elastomer attached plate mainly attributes to the thickness mode vibration of the rubber layer.In comparison with the original plate,external elastomer attached plate mainly decrease the structure self-noise caused by hydrodynamic component of turbulent pressure fluctuation,while the distance between the plate and the observation point reaches as long as 0.05 m,the reduction amplitudes of sound pressure decreases to less than 3 dB.Compared with stiffened plate,external elastomer attached stiffened plate possesses lower turbulent pressure induced structure self-noise over all wavenumber domain,while the distance between the plate and the observation point reaches as long as 0.7 m,the reduction amplitudes of sound pressure are still around 20 dB.While stringer cross section height or width becomes twice larger,the acceleration auto-spectra level of shell plate at stiffeners decreases by 3 dB,however its counterparts at other places do not variate.Basically for all positions on the plate,the variation of stringer distance has no apparent influence on the shell structure self-noise auto-spectra level.