Analysis of the radiation and transpiration heterogeneity inside a crop cover using Computational Fluid Dynamics.

Abstract : The crop activity strongly interacts with the climate inside a greenhouse. The crop exerts a mechanical strain onto the flow and exchanges heat and water vapour with the surrounding environment. Conversely, the outside climate conditions (wind, air temperature and radiation) also affect the metabolism of plants. Up to now, the mechanisms involved in the transpiration process have been largely investigated, at least experimentally. However, few numerical studies of the distributed climate including the transfers at crop level exist. In order to better control the crop behaviour and growth, it remains relevant to assess the heterogeneity of the climatic parameters (radiation, temperature, humidity) inside the canopy. A commercially available computational fluid dynamics (CFD) software was used for simulations. The modelling approach is based on the resolution of the 2D Navier-Stokes equations taking account of turbulence (standard k-e model). A submodel based on the resolution of the Radiative Transfer Equation and distinguishing short and long wavelength was implemented. The radiation reaching the plants decreased inside the canopy according to the Beer's law. The crop (Impatiens cultivar) was considered as a porous medium exchanging latent and sensible heat with the ambient environment. The latent heat flux was deduced from an energy balance over the leaves. Simulations were conducted for a 2500 m2 glasshouse equipped with continuous roof vents. The analysis focuses on two scales: the building and the canopy. The heterogeneity of the velocity, temperature and humidity distributions is first investigated. But the main point deals with the heterogeneity of the radiation reaching the canopy. This heterogeneity affects the photosynthesis process and results in complex latent and sensible heat flux distributions inside the crop.
Type de document :
Communication dans un congrès
High Technology for Greenhouse Systems - GreenSys2009, Jun 2009, Québec (CA), Canada. International Society Horticultural Science, 893 (1), pp.679-684, 2009
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Contributeur : Céline Martel <>
Soumis le : vendredi 7 septembre 2012 - 16:04:04
Dernière modification le : vendredi 29 juin 2018 - 11:54:05

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  • HAL Id : hal-00729950, version 1

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Pierre-Emmanuel Bournet, A. Kichah, Gérard Chasseriaux. Analysis of the radiation and transpiration heterogeneity inside a crop cover using Computational Fluid Dynamics.. High Technology for Greenhouse Systems - GreenSys2009, Jun 2009, Québec (CA), Canada. International Society Horticultural Science, 893 (1), pp.679-684, 2009. 〈hal-00729950〉

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