0b7afed1-98a0-4625-a127-5a3c9ad80eab20210519080248130wseas:wseasmdt@crossref.orgMDT DepositWSEAS TRANSACTIONS ON FLUID MECHANICS2224-347X1790-508710.37394/232013http://wseas.org/wseas/cms.action?id=40361420211420211610.37394/232013.2021.16https://wseas.org/wseas/cms.action?id=23282M.El JazouliLaboratoire de Thermodynamique et Energétique, Faculté des Sciences Université Ibn zohr cité Dakhla BP 8106 Agadir, MORROCOK.LekouchLaboratoire de Thermodynamique et Energétique, Faculté des Sciences Université Ibn zohr cité Dakhla BP 8106 Agadir, MORROCOΑ.WifayaLaboratoire de Thermodynamique et Energétique, Faculté des Sciences Université Ibn zohr cité Dakhla BP 8106 Agadir, MORROCOL.GourdoLaboratoire de Thermodynamique et Energétique, Faculté des Sciences Université Ibn zohr cité Dakhla BP 8106 Agadir, MORROCOL.BouirdenLaboratoire de Thermodynamique et Energétique, Faculté des Sciences Université Ibn zohr cité Dakhla BP 8106 Agadir, MORROCOUnderstanding and improving greenhouses requires the analysis and modelling of energy and mass exchange phenomena. The mastery of all these physical mechanisms can make it possible to propose technological solutions to control the greenhouse climate. This study presents an analysis and simulation of air flow, temperature and humidity patterns ,in ½-ha multi-span greenhouse with oblique side walls,covered by insect proof nets.The site is located in the coastal area of southern Morocco. The fundamental calculation of climatic conditions is based on CFD, wich uses the mass, momentum and energy conservation equations. The dynamic influence of the insect screens and tomato crop on airflow movement, was described ,using the concept of the porous medium approach proposed by Darcy and Forchheimer.The coupling of convective and radiative exchanges at the plastic roof cover is considered. A good agreement was observed between the measured and simulated values for inside air temperatures and relative humidity. Insect screens significantly reduced airflow and increased thermal gradients inside the greenhouse. The results clearly showed the heterogeneity of the greenhouse’s internal climate, which infects agricultural production in quantity and quality51920215192021102108https://www.wseas.org/multimedia/journals/fluid/2021/a225113-307.pdf10.37394/232013.2021.16.10https://www.wseas.org/multimedia/journals/fluid/2021/a225113-307.pdf10.1016/j.biosystemseng.2005.01.001Katsoulas et al Effect of vent openings and insect screens on greenhouse ventilation. Biosystems Engineering.(2006).01.001 10.17660/actahortic.2007.747.51Hanafi, A., Bouharroud. R, Mifth & Amouat. S. (2003a). Performances of two types of insect screens as a physical barrier against B. tabaci and their impact on TYLCV incidence in a greenhouse tomato in the Souss valley of Morocco. In Castané. C & Hanafi. A (Eds) Integrated control in protected crops, Mediterannean Climate.IOBC wprs Bulletin. Vol. 26 (10) : 39-42. 10.1016/j.biosystemseng.2005.11.014Fatnassi, H., Boulard. T., Poncet. C & Chave. M. (2006). 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