RADIATION FROM AND PANEL RESPONSE TO A SUPERSONIC TURBULENT BOUNDARY LAYER
BOEING SCIENTIFIC RESEARCH LABS SEATTLE WA FLIGHT SCIENCES LAB
Pagination or Media Count:
When the convection velocity of the turbulence exceeds the local speed of sound in the medium the coupling of the panel modes to the acoustic field becomes very strong. The structural damping which is usually constant for all modes is overshadowed by the acoustic damping which increases with frequency. For a boundary layer of nearly zero pressure gradient the linear theory is still useful in predicting the panel response and compares well with experiment. Using Kirchhoffs theorem the acoustic power radiated from a turbulent boundary layer was expressed in terms of the cross spectral density of the pressure field over a rigid plane surface. Computation shows that by using this method the acoustic power level agrees satisfactorily with the measurement.
- Fluid Mechanics