A time domain finite volume method（TDFVM）based on wave theory is developed to analyze the transient response and natural characteristics of structural-acoustic coupling problems in an enclosed cavity.In the present ...A time domain finite volume method（TDFVM）based on wave theory is developed to analyze the transient response and natural characteristics of structural-acoustic coupling problems in an enclosed cavity.In the present method,the elastic dynamic equations and acoustic equation in heterogeneous medium are solved in solid domains and fluid domains respectively.The structural-acoustic coupling is implemented according to the continuity condition of the particle velocity along the normal direction and the normal traction equilibrium condition on the interface.Several numerical examples are presented to validate the effectiveness and accuracy of the present TDFVM.Then the effects of water depth on the acoustic and vibration characteristics and the natural characteristics of a structural-acoustic coupling system are analyzed.The numerical results show that the increase of water depth leads to a stronger coupling between the water and structure and the decrease of natural frequencies of coupling system,The computational cost and memory of this method are small and it can be applicable to structural-acoustic coupling problems in the heterogeneous fluid.展开更多
Natural and ventilated cavitations generated on a smooth-nosed axisymmetric body were studied experimentally.The characteristics of small scale and localized fluctuations of “steady cavities” were measured by pressu...Natural and ventilated cavitations generated on a smooth-nosed axisymmetric body were studied experimentally.The characteristics of small scale and localized fluctuations of “steady cavities” were measured by pressure transducers. Comparisons between natural and ventilated cavities at different measured points for several cavitation numbers were done. It was observed that the dominant fluctuations were concentrated in the frequency range of 0Hz-50Hz for all the cavitation cases, Similar shapes and magnitudes of the frequency spectra were detected for both natural and ventilated cavities. Much larger spectral amplitude in the cavity closure region suggested al fluctuations source. From partial cavitating flow to supercavitating flow, the dominant frequency and the corresponding amplitude decreased with decreasing cavitation number, which meant that cavity became more steady while developing.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(HEUCF100307)the National Natural Science Foundation of China(51279035)
文摘A time domain finite volume method（TDFVM）based on wave theory is developed to analyze the transient response and natural characteristics of structural-acoustic coupling problems in an enclosed cavity.In the present method,the elastic dynamic equations and acoustic equation in heterogeneous medium are solved in solid domains and fluid domains respectively.The structural-acoustic coupling is implemented according to the continuity condition of the particle velocity along the normal direction and the normal traction equilibrium condition on the interface.Several numerical examples are presented to validate the effectiveness and accuracy of the present TDFVM.Then the effects of water depth on the acoustic and vibration characteristics and the natural characteristics of a structural-acoustic coupling system are analyzed.The numerical results show that the increase of water depth leads to a stronger coupling between the water and structure and the decrease of natural frequencies of coupling system,The computational cost and memory of this method are small and it can be applicable to structural-acoustic coupling problems in the heterogeneous fluid.
基金Project supported by the National Natural Science Foundation of China (Grant No: 10372061) and the Doctor Founda tion (Granted No: 20030248001).
文摘Natural and ventilated cavitations generated on a smooth-nosed axisymmetric body were studied experimentally.The characteristics of small scale and localized fluctuations of “steady cavities” were measured by pressure transducers. Comparisons between natural and ventilated cavities at different measured points for several cavitation numbers were done. It was observed that the dominant fluctuations were concentrated in the frequency range of 0Hz-50Hz for all the cavitation cases, Similar shapes and magnitudes of the frequency spectra were detected for both natural and ventilated cavities. Much larger spectral amplitude in the cavity closure region suggested al fluctuations source. From partial cavitating flow to supercavitating flow, the dominant frequency and the corresponding amplitude decreased with decreasing cavitation number, which meant that cavity became more steady while developing.
