CO-SIMULATION OF THE MICROCLIMATE INSIDE A GREENHOUSE BY COUPLING ENERGY AND CFD MODELS
Energy Simulation (ES) is an interesting tool to explore and predict the evolution of the mean climatic parameters inside a greenhouse. A limitation of this tool is that it requires the ventilation rate and the heat transfer coefficients along the walls as inputs. This information may be obtained from Computational Fluid Dynamics (CFD). The present study focuses on the coupling of a CFD code with an ES program. The coupling consists in exchanging data between ES and CFD. ES uses the ventilation rate and the convective heat coefficients provided by CFD. Conversely ES provides the wall temperatures to the CFD code as updated boundary conditions. In a preliminary stage, the greenhouse was represented by a 3D geometry and the calcula¬tion domain reduced to the greenhouse itself i.e., without surroundings. The venti¬lation rate was computed by applying the Mean Age of Air (MAA) technique in the CFD code, which implies the resolution of an additional scalar equation. The internal convective heat coefficients were also computed and transmitted to the ES model via a specific routine written under the TRNSYS environment. The obtained CFD results for the MAA were first compared with experimental data available in the literature. The mean temperature and humidity predicted by the co-simulation ES-CFD were then compared with experimental data recorded inside a plastic tunnel greenhouse located in Angers (France) and the effects of ventilation caused by the opening of the door on the greenhouse microclimate were analysed. One limitation of the approach however, is that the restriction of the CFD calculation domain to the greenhouse does not make it possible yet the CFD calculation of external heat transfers coefficients used in ES, which are still estimated from empirical correlations. This drawback should be overcome in the next developments by extending the CFD-grid to the surroundings of the greenhouse.
Serir, L. and Bournet, P.E. (2014). CO-SIMULATION OF THE MICROCLIMATE INSIDE A GREENHOUSE BY COUPLING ENERGY AND CFD MODELS . Acta Hortic. 1037, 1043-1048
TRNSYS, CFD, coupling, ventilation rate, mean age of air