Identifying the turbulent flow developing inside and around the bottom trawl by Electromagnetic Current Velocity Meter approach in the flume tank

作     者：Nyatchouba Nsangue Bruno Thierry Hao Tang Liu-xiong Xu Fuxiang Hu Xinxing You Micah Adekunle David Njomoue Pandong Achille Nyatchouba Nsangue Bruno Thierry;Hao Tang;Liu-xiong Xu;Fuxiang Hu;Xinxing You;Micah Adekunle David;Njomoue Pandong Achille

作者机构：College of Marine SciencesShanghai Ocean UniversityShanghai201306China National Engineering Research Center for Oceanic FisheriesShanghai201306China Key Laboratory of Oceanic Fisheries ExplorationMinistry of Agriculture and Rural AffairsShanghai201306China The Key Laboratory of Sustainable Exploitation of Oceanic Fisheries ResourcesShanghai Ocean UniversityMinistry of EducationShanghai201306China Scientific Observing and Experimental Station of Oceanic Fishery ResourcesMinistry of Agriculture and Rural AffairsShanghai201306China Department of Marine BiosciencesTokyo University of Marine Science and TechnologyMinatoTokyoJapan College of Fisheries and Life SciencesShanghai Ocean UniversityShanghai201306China Faculty of Industrial EngineeringUniversity of DoualaDoualaCameroon 

出 版 物：《Journal of Hydrodynamics》 (水动力学研究与进展B辑（英文版）)

年 卷 期：2021年第33卷第3期

页      面：636-656页

核心收录：

学科分类：080704[工学-流体机械及工程] 080103[工学-流体力学] 08[工学] 0807[工学-动力工程及工程热物理] 0801[工学-力学（可授工学、理学学位）] 

基　　金：Projects supported by the National Natural Science Foundation of China(Grand No.31902426).v This work was supported by the Shanghai Sailing Program(Grant No.19YF1419800) the Special project for the exploitation and utilization of Antarctic biological resources of Ministry of Agriculture and Rural Affairs(Grant No.D-8002-18-0097) 

主　　题：Hydrodynamic bottom trawl net turbulent flow Electromagnetic Current Velocity Meter(ECVM) turbulence intensity proper orthogonal decomposition(POD) 

摘      要：The Knowledge of turbulent flow developing inside and around the bottom trawl net is of great importance not only for improving the hydrodynamic performance of the gear but also for the selectivity via the fish response,such as the herding response or escape *** 3-D Electromagnetic Current Velocity Meter(ECVM)measurements were performed to investigate the effect of turbulent flow on the bottom trawl net performance and to analyze the turbulence intensity and velocity ratio inside and around different parts of the trawl *** orthogonal decomposition(POD)method was applied in order to extract the phase averaged mean velocity field of turbulent flow from each available ECVM instantaneous *** results demonstrated the existence of turbulence flow,consisting of turbulent boundary layer flow and the turbulence due to the trawl wake developing all inside and around the bottom trawl *** input streamwise velocity results in faster trawl movement and a significant turbulent *** maximum turbulence intensity inside and around trawl wing,square part,first belly,second belly,third belly,cod-end is 0.95%,1.34%,3.40%,4.10%,4.25%and 3.80%,*** was found that the mean velocity field in a turbulent flow inside and around trawl net cod-end recovered on the average was~77.58%of the input streamwise *** is~12.92%,~13.07%,~11.40%,~13.00%and~0.45%less than that inside and around trawl wing,square part,first belly,second belly,and third belly of the bottom trawl net,*** turbulent flow behavior depends strongly on the structure oscillation,input streamwise velocity and,porosity of the net *** is necessary to take into account the velocity reduction inside and around a different part of the trawl net to improve the entire drag force determination,cod-end design,and further selectivity control of the fishing gear.