Experimental results and spatial simulation of climate in a greenhouse with insect screens

Abstract

Aim of the present paper was to present, analyze and compare detailed experimental data and CFD simulation results in a greenhouse equipped with insect screens. The studied greenhouse was a round arch type with vertical side walls. A tomato crop was cultivated inside the greenhouse with a mean height during the period of measurements of 1.8 m. Air velocity, temperature and humidity measurements at 72 positions equally distributed inside the greenhouse were carried out by means of a 3-D sonic anemometer and a fast response temperature and humidity sensor, while in parallel, outside climate variables were also recorded. For the numerical part, the commercial CFD code Fluent was used as a basis, where the required external source code for the various sub-models and boundary conditions were embedded. Good overall agreement, both quantitative and qualitative was found between the experimental and simulated data. The differences between measured and computed by the CFD model values were between 0.01 to 0.18 m s -1 for air velocity, 0.1 to 1.3°C for air temperature and 0.15 to 0.6 kPa for air vapour pressure. Quantitative understanding of the climate heterogeneity induced by ventilation and insect screens on greenhouse can help to improve the design of vent openings and thus, to optimize greenhouse production in terms of cost efficiency, crop quality and quantity.