基于空化射流技术的养殖网箱水下清洗喷嘴数值模拟  

Numerical simulation of underwater cleaning nozzle of aquaculture cage based on cavitating jet technology

作　　者：林礼群 刘平[1,2] 王志勇 LIN Liqun;LIU Ping;WANG Zhiyong(Fishery Machinery and Instrument Research Institute,Chinese Academy of Fishery Science,Shanghai 200092,China;Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,Shandong,China)

机构地区：[1]中国水产科学研究院渔业机械仪器研究所,上海200092 [2]青岛海洋科学与技术国家实验室,山东青岛266237

出　　处：《渔业现代化》2020年第5期59-65,共7页Fishery Modernization

基　　金：山东省重大科技创新工程项目“深远海鱼类养殖专用设备研制(2018CXGC0106)”;现代农业人才支撑计划“远洋渔船与装备研发创新团队(2016RS001)”。

摘　　要：网衣附着生物形成堵塞是深海网箱养殖面临的严重问题之一,如何实现养殖网箱的安全高效清洗是目前亟待解决的问题。研究了网箱水下清洗机器人结构,将空化射流技术应用于养殖网箱表面附着物的清洗,根据网箱水下清洗工况,利用Fluent软件对喷嘴内部的空化流场进行了数值模拟,采用mixture气液两相模型、空化模型和Realizable k-ε湍流模型模拟计算得到了喷嘴附近速度流场和气相体积分数的分布规律;还研究了喷嘴入口压力和清洗深度对空化射流空化效果的影响。结果显示,空化现象主要产生于喷嘴圆扩张段壁面,增大喷嘴入口压力有利于提高流体射流速度及高速流射程范围,有效提高空化程度,增强清洗打击力,但水深深度增加不利于空化。该模拟计算结果可为空化射流在网箱养殖水下清洗应用提供一定理论参考。Net clogging by attached organisms is one of the serious problems in deep sea aquaculture cage.How to realize the safe and efficient cleaning of cage is an urgent problem.In this paper,the structure of cage underwater cleaning robot was studied,and cavitating jet technology was used to clean the attachment on the surface of cage.The cavitation flow field inside the nozzle was simulated numerically by FLUENT software according to the underwater cleaning condition of the cage.The distribution of velocity field and vapor volume fraction near the nozzle was obtained by means of mixture model,cavitation model and Realizable k-εturbulence model.The influence of nozzle inlet pressure and cleaning depth on cavitation effect of cavitating jet was also studied.The results show that the cavitation mainly occurs on the wall of the nozzle expansion section.Increasing the nozzle inlet pressure can improve the jet speed and high-speed flow range,and effectively improve the cavitation intensity,so as to enhance the cleaning strike force.However,with the increase of water depth,cavitation will be weakened.The results can provide a theoretical reference for the application of cavitating jet in aquaculture cage.

关 键 词：养殖网箱 水下清洗 空化射流 数值模拟 

分 类 号：S951.3[农业科学—水产养殖]