Finite element modelling and simulation of a natural ventilation greenhouse
Authors: Dev, S, Og Clark, M Lefsrud, P Adewale, Jd Martinez
Description: Greenhouse production is a favourable technique for growing crops in places where extreme weather conditions are an issue and is gaining increasing importance in the agricultural industry. A uniform indoor microclimate allows optimum production of horticultural plants with uniform product quality, which facilitates an organized harvest. Improved control of the climatic variables result in higher standards of quality and more efficient production. Natural ventilation involves the exchange of air between the inside and outside of a greenhouse due to temperature and wind gradients, as well as the movement of air within the greenhouse including heat exchange between the vegetation and the interior greenhouse air. Winds dominate the ventilation process depending on its velocity. The effects of side vents, roof vents and greenhouse size and scaling on natural ventilation are not clearly understood. Proper ventilation rates and a uniform growing environment are, nonetheless, strongly influenced by such design elements. Therefore studies on natural ventilation for existing greenhouse designs and a new proposed design of a greenhouse were conducted using a Computational Fluid Dynamics model to evaluate airflow patterns and ventilation rates within a small-scale greenhouse and a multi-span greenhouse for varying temperatures and external wind speeds. The simulation results were validated using data available in the literature and data collected from existing greenhouses. These simulation models can act as a valuable optimization tool for various design parameters involved in designing and building multi-span greenhouses.
Keywords: numerical simulation, greenhouse, ventilation, finite element model
Technical field: technical_fields_app1
Session name: Biological systems