On acoustic radiation from a vibrating panelAn experimental and numerical study of the response and radiation from an acoustically loaded aircraft panel is presented. In the experiment, the panel is excited by a normally incident, harmonic wave. Measurements of the panel response and the resulting transmitted pressure are made in both the near- and acoustic far-fields. The numerical computations model the experiment and in particular account for the full coupling between the panel and the surrounding three dimensional acoustic fluid. The results demonstrate that for a sufficiently high excitation level, the panel response becomes nonlinear. The nonlinearity is characterized by the appearance of harmonics and subharmonics in the power spectral densities of the panel motion and consequently in the resulting acoustic radiation. The primary characteristic of the far-field acoustic radiation is the increase in harmonic content relative to the fundamental and subharmonics with increasing distance from the panel. This is shown to be a result of linear and weakly nonlinear wave propagation effects. The numerical results show that the radiated far-field pressure is strongly dependent on the position of the measurement point with respect to the panel center. The experimental and numerical results are in good qualitative agreement.
Document ID
19940034695
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Frendi, Abdelkader (Analytical Services and Materials, Inc. Hampton, VA, United States)
Maestrello, Lucio (NASA Langley Research Center Hampton, VA, United States)
Robinson, Jay (NASA Langley Research Center Hampton, VA, United States)
Bayliss, Alvin (Northwestern Univ. Evanston, IL, United States)