COUPLING BETWEEN ACOUSTIC RESONANCE AND FLUIDELASTIC INSTABILITY IN NORMAL TRIANGULAR TUBE ARRAYS

摘要

This paper reports on the interaction between fluidelastic instability (FEI) and acoustic resonance. In order to examine the interaction, the duct acoustics were excited with speakers placed adjacent to the tube array to artificially replicate flow-induced acoustic resonance. While the current study has clearly captured the phenomenon of interaction between the fluidelastic motion at ～10Hz and the acoustic field at ～ 1kHz, it is not apparent what the physical mechanism at work might be. The paper details the effect on RMS level of tube vibration for three independent parameters: flow velocity, structural damping and acoustic power. The results presented show that there is a corresponding fall in the FEI vibration amplitude with increasing sound pressure level in the tube array. In addition, the effects of flow velocity and structural damping in conjunction with forced acoustics on the RMS of tube displacement are discussed.