Bubble Size Distribution for Waves Propagating over A Submerged Breakwater  

作　　者：TIEN Tsung-mo HUANG Ching-jer HSU Tai-wen LEE Chien-hsun HSU Shi-sheng 

机构地区：[1]Department of Hydraulic and Ocean Engineering, National Cheng Kung University

出　　处：《China Ocean Engineering》2008年第2期227-240,共14页中国海洋工程（英文版）

摘　　要：Experiments are carried out to study the characteristics of active bubbles entrained by breaking waves as these propagate over an abruptly topographical change or a submerged breakwater. Underwater sounds generated by the entrained air bubbles are detected by a hydrophone connected to a charge amplifier and a data acquisition system. The size distribution of the bubbles is then determined inversely from the received sound frequencies. The sound signals are converted from time domain to time-frequency domain by applying Gabor transform. The number of bubbles with different sizes are counted from the signal peaks in the time-frequency domain. The characteristics of the bubbles are in terms of bubble size spectra, which account for the variation in bubble probability density related to the bubble radius r. The experimental data demonstrate that the bubble probability density function shows a - 2.39 power-law sealing with radius for r 〉 0. 8 mm, and a- 1.11 power law for r 〈0.8 mm.Experiments are carried out to study the characteristics of active bubbles entrained by breaking waves as these propagate over an abruptly topographical change or a submerged breakwater. Underwater sounds generated by the entrained air bubbles are detected by a hydrophone connected to a charge amplifier and a data acquisition system. The size distribution of the bubbles is then determined inversely from the received sound frequencies. The sound signals are converted from time domain to time-frequency domain by applying Gabor transform. The number of bubbles with different sizes are counted from the signal peaks in the time-frequency domain. The characteristics of the bubbles are in terms of bubble size spectra, which account for the variation in bubble probability density related to the bubble radius r. The experimental data demonstrate that the bubble probability density function shows a - 2.39 power-law sealing with radius for r 〉 0. 8 mm, and a- 1.11 power law for r 〈0.8 mm.

关 键 词：breaking waves submerged breakwater underwater noise Gabor transform bubble-size spectra 

分 类 号：TV131.3[水利工程—水力学及河流动力学]