Numerical Analysis Of Mechanically Ventilated Venlo-Type Greenhouse

With the fast development of the computer technology, the computing power of CFD (Computational Fluid Dynamics) software, like FLUENT, has got great improvement, which results in revolutionary advancement in the design study. The field of vision of greenhouse structural designing was broadened by applying CFD method in the greenhouse researches, showing CFD's great potential in scientific and practical application.This dissertation took the Venlo-Type glasshouse as the research object, analyzed the greenhouse thermal environment under Mechanical ventilation condition, and verified the primary factors affecting greenhouse thermal environment, upon which based the reasonable simplification for the CFD model. Then definition of the computation domain, the form of the flow field governing equations, and the choice of rapids model and radiation model as well were proposed for CFD simulation.Experiments in the greenhouse under mechanically ventilated condition were performed to collect data about temperature distribution inside the greenhouse both in vertical and horizontal directions, and weather data outside as well, providing data resources for the set of parameters in the CFD model. Data analysis was carried out to complete the definition of the boundary conditions and the establishment of the CFD validation model. The greenhouse thermal environment under mechanical ventilation was simulated employing the CFD model constructed before. The numerical results got good agreement with the experiment data, which confirmed the accuracy of the definition of the boundary conditions and the validity of the CFD model.On the basis of the above research, the CFD method was used to simulate the cooling effect under different greenhouse structure configurations like the use of the Inner curtain and the arrangement of different height of cooling shade and fan and also the coordinated disposition between different length of greenhouse and height of cooling pad.The optimization design of parameter for the overall construction of the greenhouse has carried on the preliminary discussion which can provide the theory basis for the Venlo-Type greenhouse structure's optimization.