利用CFD-DEM耦合的水射流清洗猪粪过程数值模拟与验证  

Numerical simulation and validation of water jet cleaning of pig manure using CFD-DEM coupling

作　　者：刘凯歌 周昕 徐杏 赵先亮[1] 潘梓博 路伏增[2] 吉洪湖 蔡静 周卫东 LIU Kaige;ZHOU Xin;XU Xing;ZHAO Xianliang;PAN Zibo;LU Fuzeng;JI Honghu;CAI Jing;ZHOU Weidong(College of Biology and Chemical Engineering,Zhejiang University of Science and Technology,Hangzhou 310023,China;Institute of Animal Husbandry and Veterinary Medicine,Zhejiang Academy of Agricultural Sciences,Hangzhou 310021,China;Zhejiang Agricultural Machinery Research Institute,Jinhua 321017,China)

机构地区：[1]浙江科技学院生物与化学工程学院,杭州310023 [2]浙江省农业科学院畜牧兽医研究所,杭州310021 [3]浙江省农业机械研究院,金华321017

出　　处：《农业工程学报》2023年第23期204-211,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：浙江省重点研发计划项目(2021C02050);宁波市科技计划项目(022Z178);浙江省农业科学院专项经费项目(2023R22CB001)。

摘　　要：为探究水射流清洗猪粪的过程和效果,利用计算流体力学和离散元法(computational fluid dynamics-discrete element method,CFD-DEM)耦合对水射流清洗猪粪过程进行数值模拟与验证。结果表明:1)水射流清洗猪粪过程分为三个阶段:自由射流清洗、淹没射流清洗、冲击强化,水射流到达猪粪层表面后0.45 s内清洗效率最高;2)在同结构参数和工作压力下,锥形喷嘴清洗效果优于直锥形喷嘴,连续清洗0.45 s作用时长锥形喷嘴清洗量比直锥形喷嘴高约0.83%;3)锥形喷嘴最大水平清洗移速与清洗目标深度、工作压力负相关,与喷嘴出口直径无明显关系,其中清洗目标深度影响最大。该研究提出了60%含水率的猪粪颗粒粗粒建模方法,并通过清洗试验验证了耦合仿真的有效性,研究结果可为畜禽粪污清洗装备的设计与优化提供理论参考。Pork is the second most consumed meat in the world.The scale and intensification of pig farming have been everincreasing in recent years.It is required for the continuous development of Precision Livestock Farming technologies.Cleaning inside the house is one of the most important parts of precision pig farming.Among them,the water jet cleaning pig manure is assumed as a two-phase flow of water-pig manure particles.This study aims to investigate the process and effect of water jet cleaning pig manure.Numerical simulations were conducted to simulate the two-phase interaction between the water jet and pig manure using computational fluid dynamics(CFD)and discrete element method(DEM).Firstly,the water jet flow field model was established to complete the flow net independence verification for the grid partitioning using Fluent software.Then,the pig manure particle model was constructed using Rocky.The relative error between the simulation and the actual measurement was 1.78%,indicating the reliability of the pig manure physical properties parameters and the pig manure simulation model.A linear adhesion model was introduced to optimize the pig manure model using coarse-grained modeling.The total number of particles was also reduced for the less computational complexity during simulation.Finally,fluid-solid coupling experiments were conducted using Fluent-Rocky DEM.The experiments were carried out to simulate the vertical impact cleaning of a pig manure layer at a distance of 300mm from the nozzle outlet using a water jet.The results showed that:1)The process of water jet cleaning pig manure was divided into three stages:free jet cleaning,submerged jet cleaning,and impact strengthening.The water jet flew from the nozzle inlet and stabilized on the surface of the pig manure layer after approximately 0.3 s.As the cleaning time increased,the pig manure layer showed bowl-shaped pits with a central peak forming at the center of the pit.2)The highest cleaning efficiency occurred within 0.45 s after the continuous water jet r

关 键 词：模拟 水射流 喷嘴 CFD-DEM 清洗 流固耦合 

分 类 号：S22[农业科学—农业机械化工程]