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ISSN Печать: 1064-2285
ISSN Онлайн: 2162-6561
Indexed in
Numerical Simulation of Natural Convection in a Horticultural Greenhouse Heated from Below (by Using CFD)
Краткое описание
The analysis of the possibility of determining climate under a greenhouse confronts us with a very complex system composed at least of three components (culture, substrate or soil, and air) and of exchange of energy, steam, and CO2 between them. The recent advance of greenhouse surfaces in the Mediterranean basin puts in the forefront the problem of air-conditioning whose solution will improve production at least as far as the quality is concerned. This work is concerned with numerical simulation of natural convection in a laminar regime in closed greenhouses (tunnel greenhouse and single span greenhouse) of length 25 m, width 6 m, and height 3.5 m, intended for planting vegetation for the table with soil heated by a flux of 100 W. The walls of a single span greenhouse are adiabatic, the roof is maintained at a temperature of 280 K in both greenhouses. For all the walls of the two greenhouses and the soil in them the conditions of adhesion hold: u = v = w = 0 m/sec. The model suggested represents the equation of motion associated with an energy equation; it is solved by means of a Computational Fluid Dynamic software (CFD2000) based on the PISO algorithm. The results are represented in the form of streamlines, isotherms, and velocity profiles. The results obtained allow one to characterize the general flow of air in a greenhouse. It is also shown that for the conditions of flux application to soil (heating by means of a buried tube), the circulation of air is characterized by two recirculation cells rotating in the opposite directions. Therefore, this study will permit one to improve thermal designs of greenhouses and positioning of air-conditioning systems.
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Oztop Hakan F., Varol Yasin, Koca Ahmet, Laminar natural convection heat transfer in a shed roof with or without eave for summer season, Applied Thermal Engineering, 27, 13, 2007. Crossref
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Kaluri Ram Satish, Anandalakshmi R., Basak Tanmay, Bejan’s heatline analysis of natural convection in right-angled triangular enclosures: Effects of aspect-ratio and thermal boundary conditions, International Journal of Thermal Sciences, 49, 9, 2010. Crossref
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Koca Ahmet, Oztop Hakan F., Varol Yasin, Numerical analysis of natural convection in shed roofs with eave of buildings for cold climates, Computers & Mathematics with Applications, 56, 12, 2008. Crossref
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SLATNİ Yassine, DJEZZAR Mahfoud, MESSAİ Tarek, NUMERICAL INVESTIGATION OF NATURAL CONVECTION WITH HEATED TUBES IN TUNNEL GREENHOUSE, Journal of Thermal Engineering, 2021. Crossref