机构地区:[1]南京农业大学工学院,南京210031 [2]常州市阳湖鹅业专业合作社,常州213101 [3]江苏省农业科学院畜牧研究所,南京210014
出 处:《农业工程学报》2017年第3期214-220,共7页Transactions of the Chinese Society of Agricultural Engineering
基 金:江苏省农业科技自主创新项目(CX(15)1008);国家现代农业产业体系项目(CARS-43-16)
摘 要:针对鹅舍内机械通风时大量气流扩散于鹅舍上方而位于地面鹅只通风效果受阻的气流问题,提出一种基于计算流体力学(computational fluid dynamics,CFD)的结构优化方案。通过在舍内主梁下端安装相同高度且与气流方向呈一定倾角的多个可拉伸卷膜构造方法,提高种鹅舍内有效的通风效率。依据试验现场边界条件,构建并求解了鹅舍的三维稳态模型,舍内40个测点的风速模拟值与实测值均方根误差为0.152 m/s,最大绝对误差为0.29 m/s,平均相对误差为2.04%,验证了建立的鹅舍CFD模型的准确性。根据不同优化方案数值模拟了27组不同改造后鹅舍内气流场分布情况,仿真得出最优组合方案:在42 m长的舍内安装卷膜个数为10个,卷膜与主梁竖直方向倾斜角度为60o以及卷膜最大下拉高度为1.2 m时舍内通风效率最高、气流分布最均匀。通过现场实测,对比改造前后40个测点的风速值,试验结果表明:改造后鹅舍较常规鹅舍平均风速增加0.527 m/s,舍内气流不均匀系数降低32.2%。该试验结果为种鹅舍的结构设计、同类型畜禽舍结构优化以及改善通风降温效果调控提供了一定的参考依据。Goose is seasonal breeding animal, the goslings and adult geese supply show seasonal changes, so that the sale priceof the geese is fluctuating. The out-of-season breeding technology was employed to balance annual goose production andachieve higher economic benefits by regulating the normal breeding of geese in the spring and summer of non-breeding seasonThis technique has been popularized in the last few years, however, the high temperature in the summer is adverse to the gooseproduction in the process of out-of-season breeding. It is known that the quality of thermal environment and the concentrationof harmful gases are important factors to the health of livestock. In order to reduce or eliminate adverse effects of heat stressand lack of water on the geese during the process of out-of-season breeding, the ventilation-cooling mode with fans andevaporative pad was employed in conventional goose house, while a large amount of airflow diffusion located in the upper partof the goose house due to that these airflow of small density flowed upward. The use of computational fluid dynamics (CFD)techniques to solve complex fluid problems has greatly increased in the last few years. In this study, the goose house withmechanical ventilation had a large number of airflow diffusion in the upper part of the goose house, this may cause a problemthat the ventilation effect of the ground geese was obstructed. So a structure optimization scheme based on computational fluiddynamics (CFD) has been proposed, multiple stretching film structures were installed below the girders of goose house tochange the airflow directions as well as to increase the airflow flux in the lower part of goose house around the geese. Basedon that, the two factors of vertical angle between stretching film and girder, drop height of stretching film were investigated toobtain uniform airflow and higher ventilation efficiency in the goose house. A three-dimensional steady goose house modelwas developed by the field measured boundary conditions data. Co
关 键 词:计算流体力学(CFD) 优化 流场 鹅舍 卷膜构造 通风效果 数值模拟
分 类 号:S219[农业科学—农业机械化工程]
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