Computational analysis of ventilation in greenhouses at zero-and low-wind-speeds

A systematic analysis of the natural ventilation process in greenhouses at no-wind and low-wind- speed conditions was performed with the use of Computational Fluid Dynamics (CFD). The validity of this approach was first checked with success by comparing the numerical results with experimental data obtained from the literature. Numerical predictions of the ventilation efficiency of typical Mediterranean-type greenhouses were obtained for various ventilator configurations. These computer simulations were based on a realistic representation of the heat sources and the boundary conditions related to the problem. The contribution of specific ventilators to the greenhouse air renewal was analysed. The importance of side-wall ventilators for an efficient thermally driven ventilation (‘buoyancy effect’) was confirmed. It was demonstrated that CFD is a powerful tool for developing improved designs with respect to ventilation efficiency.