Accession Number : AD0705098

Title :   RESPONSE OF FLEXIBLE PANELS TO TURBULENT BOUNDARY LAYER EXCITATION.

Descriptive Note : Technical rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE ACOUSTICS AND VIBRATION LAB

Personal Author(s) : Moore,James A.

Report Date : JUL 1969

Pagination or Media Count : 88

Abstract : The vibratory response of thin flexible panels excited by turbulent boundary layer pressure fluctuations is measured experimentally in order to investigate the effects of hydrodynamic coincidence on panel response. Experimentally determined cross correlations and cross spectral densities of the panel response are used to investigate the presence of travelling waves in the panel response in comparison with standing wave response. The various mechanisms for damping of panel response are examined. Values for radiation damping coefficients are experimentally evaluated and compared with analytically derived results. Values for purely mechanical damping coefficients are experimentally determined and compared with values for the total damping in the system that were determined from experiments involving the decay of energy in the panel. The radiation damping in air is shown to be negligible compared with the mechanical damping. The comparisons between damping values show acceptable agreement. Verification of the presence of connected wave patterns in the panel response is obtained only for limited test conditions. (Author)

Descriptors :   (*SHIP NOISE, *TURBULENT BOUNDARY LAYER), (*SHIP PLATES, VIBRATION), RESPONSE, FLEXIBLE STRUCTURES, PRESSURE, HYDRODYNAMICS, DAMPING, THESES

Subject Categories : Marine Engineering
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE