ON THE DETERMINATION OF THE CONVECTIVE HEAT TRANSFER COEFFICIENT AT THE GREENHOUSE COVER UNDER SEMI ARID CLIMATIC CONDITIONS
| Autor: | A. Soudani, K. Mesmoudi, Pierre-Emmanuel Bournet, S. Bougoul |
|---|---|
| Přispěvatelé: | Unité de Recherche Environnement Physique de la plante Horticole (EPHOR), AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université d'Angers (UA), Université d'Angers (UA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro) |
| Rok vydání: | 2012 |
| Předmět: |
0106 biological sciences
Convection Convective heat transfer Turbulence Energy balance Enclosure Greenhouse semi-arid climate 02 engineering and technology Heat transfer coefficient 15. Life on land Horticulture Atmospheric sciences energy balance 01 natural sciences Arid 020303 mechanical engineering & transports 0203 mechanical engineering 13. Climate action greenhouse [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph] [SPI.MECA.THER]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph] Environmental science 010606 plant biology & botany |
| Zdroj: | Xxviii International Horticultural Congress on Science and Horticulture for People Xxviii International Horticultural Congress on Science and Horticulture for People, Jun 2010, Protugal (PT), Portugal. 8 p Scopus-Elsevier |
| ISSN: | 2406-6168 0567-7572 |
| DOI: | 10.17660/actahortic.2012.927.76 |
| Popis: | Crop cultivation in greenhouses under semi-arid climatic conditions is subject to various stresses, in particular during the winter season at night, when the interior air is poorly controlled, leading to prolonged periods of low temperature. The aim is then to evaluate and control the heat exchanges of the enclosure in order to prevent low indoor air temperatures and reduce the thermal load of the greenhouse. The objectives of this study are to investigate the convective and radiative heat exchanges at the cover in order to establish new correlations for the convective heat transfer coefficients in semi arid regions. The climatic parameters were measured inside and outside a closed empty glasshouse without crop, for three different nights during the winter season in the semi-arid land of Algeria. A physical model for analysing the convective heat transfers was implemented, and new correlations were established, parameterised, calibrated and validated thoroughly. A significant difference was observed between the correlations obtained by this study and the models obtained for other greenhouse designs under different climatic conditions. Results show that the convection mode along the inside wall of the cover is free turbulent. Conversely, the convection mode along the outside greenhouse cover remains forced turbulent. A consistent performance of the correlations was observed, both in the calibration and validation stages. |
| Databáze: | OpenAIRE |
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