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基于风洞系统的生菜空气动力学研究 |
张晨1,2, 方慧1,2, 程瑞锋1,2, 杨其长1,2, 魏晓然1,2, 吴晨溶1,2
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(1.中国农业科学院 农业环境与可持续发展研究所, 北京 100081;2.农业农村部 设施农业节能与废弃物处理重点实验室, 北京 100081) |
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摘要: |
针对目前利用计算流体力学软件(Computational fluid dynamics,CFD)进行植物工厂内部气流模拟仅在空载植物工厂中进行,忽略了生菜对气流存在阻碍的问题,采用风洞试验,对生菜冠层空气动力学参数进行研究。利用风洞系统测定了生菜冠层的阻力系数(CD),并求得在不同叶面积密度(L)的情况下生菜冠层渗透率(K)与动量损失系数(Cf)之间的关系,将生菜栽培板置于风洞试验段中间位置,分别测量风洞试验段竖直方向和水平方向不同测点位置的稳态压力与风速。通过已求得的参数得到CFD建模中建立生菜多孔介质模型需要的粘滞阻力系数与惯性阻力参数。结果表明:1)本试验测得的生菜冠层阻力系数为0.02;2)成熟生菜(L=32.5 m2/m3),其渗透率为0.04 m2,动量损失系数为0.13;3)动量损失系数Cf取值为0.1~1.0,当叶面积密度L为10、20、30 m2/m3时,作物冠层渗透率K的取值范围分别为0.25~25.00、0.06~6.25、0.03~2.78 m2;4)成熟生菜的粘滞阻力系数为25,惯性阻力系数为1.3。 |
关键词: 风洞 生菜 多孔介质 阻力系数 渗透率 动量损失系数 |
DOI:10.11841/j.issn.1007-4333.2019.12.11 |
投稿时间:2019-04-04 |
基金项目:宁夏回族自治区重点研发计划项目(2018BBF02012);中央级公益性科研院所基本科研业务费专项(Y2019XK21-01) |
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Aerodynamic properties of lettuce canopy based on wind tunnel system |
ZHANG Chen1,2, FANG Hui1,2, CHENG Ruifeng1,2, YANG Qichang1,2, WEI Xiaoran1,2, WU Chenrong1,2
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(1.Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China;2.Key Laboratory of Energy Conservation and Waste Management of Agriculture Structures, Ministry of Agriculture and Rural Affairs, Beijing 100081, China) |
Abstract: |
Aiming at the problem that the computational fluid dynamics software (CFD),which is used to simulate the airflow in the plant factory at present,ignores the obstructing airflow of lettuce.An wind tunnel experiment is conducted to study the aerodynamic parameters of lettuce canopy.The drag coefficient of lettuce canopy (CD) is determined by using wind tunnel system,and the relationship of lettuce canopy permeability (K) and momentum loss coefficient (Cf) in different leaf area density is investigated under the condition of (L) that the relationship between the place lettuce planting plate in the middle of their wind tunnel test section and measured vertical and horizontal direction under different measuring locations of the static pressure and wind speed.The viscous resistance coefficient and inertial resistance parameters required for the establishment of lettuce porous media model in CFD modeling are obtained through the obtained parameters.The results show that:1) The resistance coefficient of lettuce canopy measured in this experiment is CD=0.02;2),the permeability is 0.04 m2,and the momentum loss coefficient is 0.13 of mature lettuce (L=32.5 m2/m3);3) The values of the nonlinear momentum loss coefficient Cf are 0.1-1.0,and when the leaf area density L is 10,20,and 30 m2/m3,the values of the canopy permeability K are 0.25-25.00,0.06-6.25,and 0.03-2.78 m2,respectively;4) The viscous resistance of the mature lettuce is 25,inertial resistance factor is 1.3. |
Key words: wind tunnel lettuce canopy porous media resistance coefficient permeability momentum loss coefficient |