Time-frequency analysis of internal waves generated by a towed and self-propelled submerged body model  

作　　者：Yu-hang Li Fei-yu Chen Li-ping Qin Ke Chen Yun-xiang You 

机构地区：[1]Zhengzhou Electromechanical Engineering Research Institute,Zhengzhou,450015,China [2]Henan Key Laboratory of Underwater Intelligence Equipment,Zhengzhou,450015,China [3]State Key Laboratory of Ocean Engineering,Shanghai Jiao Tong University,Shanghai,200240,China [4]Yazhou Bay Institute of Deepsea Technology,Shanghai Jiao Tong University,Shanghai,200240,China

出　　处：《Journal of Hydrodynamics》2023年第6期1191-1207,共17页水动力学研究与进展B辑（英文版）

基　　金：supported by the and the National Natural Science Foundation of China(Grant Nos.51979279,52275138);supported by the Natural Science Foundation of Hainan Provincial(Grant No.520MS071).

摘　　要：The spectrogram,based on a short-time Fourier transform,can visualize the time-dependent frequency spectrum of waves and is easy to compute.This time-frequency analysis method provides crucial information about waves generated by moving vessels and has been utilized to analyze Kelvin ship waves and internal waves.To further study the internal waves induced by a submerged body,an experiment is conducted for the towed and self-propelled SUBOFF model in a stratified fluid.The internal wave elevation signals are captured using electronic conductivity probes.Comparing with the calculation results of theoretical model,the high-frequency component of internal waves is identified.The high-frequency component has the exact same characteristics in both the towed and self-propelled model experiment and is consistent with the theoretical results for all Froude numbers.Therefore,this component is composed mainly of lee waves.Through spectral characteristics identification,a low-frequency component is discovered in the spectrogram in addition to the lee wave component.The intensity of the low-frequency component is tightly related to the vortex structure behind the submerged body.The vortex structure depends on the net momentum imparted by the submerged body.Therefore,this component is composed mainly of wake waves induced by the vortex structure.

关 键 词：Stratified fluid internal waves submerged body experimental study time-frequency analysis 

分 类 号：TV139.2[水利工程—水力学及河流动力学]