利用CFD模型研究日光温室内的空气流动

Airflow simulation in solar greenhouse using CFD model

在温室内空气流动对室内环境具有重要调节作用,因此有必要研究日光温室内空气流动特性。基于计算流体动力学CFD(computational fluid dynamics)方法,运用大型计算流体动力学软件Fluent对日光温室建立模型,采用标准湍流模型对日光温室内气流分布进行了三维稳态求解。模拟时将日光温室内外空气作为研究对象,并且温室内空间连同其周围的一部分室外空间一起作为CFD模拟的计算领域。对日光温室内气流变化及分布进行了数值模拟,并在温室内进行了气流试验测试,对测量值和计算所得的风速值进行了比较,结果表明,二者最大误差小于9%,说明风速的实测值和模拟值吻合良好,CFD模型有效,且得到了日光温室内部流场速度分布。通过气流流场模拟结果分析表明,直观显示了日光温内的流场特性和流动状态,气流从窗户进入沿着底部通风口流出日光温室,并且气流在底部通风口速度分布较均匀,在温室下部形成了较为明显的涡流。该文模拟结果可为东北地区日光温室的优化设计以及温室环境调节等方面提供理论依据。

Air flow plays an important role in regulating the indoor environment for the northeast regional greenhouse, therefore it is necessary to study the air flow characteristics in the solar greenhouse. The Fluent software was used to establish solar greenhouse model based on the computational fluid dynamics （CFD） method. The three-dimensional numerical simulation was done based on the standard turbulence model for the solar greenhouse. During simulation process, taking inside and outside the air in solar greenhouse as the research object, interior space along with its surrounding outdoor space was regarded as part of the CFD calculation field. Air distribution and change in solar greenhouse was numerically simulated and tested, and wind speed of numerical simulation was compared with that of experiment data. The results showed that the maximum error between them was less than 9%, and the numerical results had a good agreement with the experiment data, and the distributions of velocity of flow fields were obtained from the simulated results of solar greenhouse. The simulation results simulated airflow state that airflow flowed in from windows and then out along the bottom vents of solar greenhouse and the speed of air at bottom of air vents was uniformly distributed with eddy current formed at the bottom of solar greenhouse. The simulated results directly showed its properties and state of the flow fields. In this paper, the simulation results provide a theoretical basis for optimization design and environmental regulation for the northeast region of solar greenhouse.