Numerical simulation of solar radiation, air flow and temperature distribution in a naturally ventilated tunnel greenhouse

Catherine Baxevanou 1 , Dimitrios Fidaros 1 , Thomas Bartzanas 1 , Constantinos Kittas 1,2 (1. Center for Research and Technology-Thessaly , Institute of Technology and Management of Agricultural Ecosystems , Technology Park of Thessaly , 1 st Industrial Area , 38500 Volos ; 2. University of Thessaly , Department of Agriculture , Crop Production and Agricultural Environment , Fytokou St. , N. Ionia , GR -38446, Magnesia , Greece ) Abstract: The effect of solar radiation distribution in a typical agricultural building was numerically investigated, taking into account the thickness of the cover, its spectral optical and thermal properties. A two dimensional mesh was used to render the building's geometry, and the Discrete Ordinate (DO) model for simulating the radiation, taking into accounts its spectral distribution in three wavelength bands. Based on the meteorological data of October for the region of Volos (Greece), two parametric studies were carried out, dealing with the variation of intensity and angle of the incoming solar radiation and with the optical properties differentiation of covering materials. The flow recirculation, due to the buoyancy effect, showed the importance of internal temperature gradients, although forced convection which resulted from natural ventilation was dominant. It was concluded that cover material with high absorptivity deteriorate the natural ventilation increasing the air temperature by convection, and favoring the development of secondary recirculation where the air is trapped. Furthermore, high absorptivity reduces the available Photosynthetically Active Radiation (PAR) but it distributes it equally inside the greenhouse. Finally, the ability of the material to transmit the solar irradiance in the wavelengths corresponding to PAR with comparable absorptivity improved as the refractive index decreased. Keywords: g reenhouse, microclimate, CFD, r adiation, m ixed heat transfer, v entilation, Greece Citation: Catherine Baxevanou, Dimitrios Fidaros, Thomas Bartzanas , Constantinos Kittas . Numerical simulation of solar radiation, air flow and temperature distribution in a naturally ventilated tunnel greenhouse . Agric Eng Int : CIGR Journal , 20 1 0 , 12 ( 3 ): 48 - 67 .

[1]  Antonio F. Miguel,et al.  Solar irradiation inside a single span greenhouse , 1989 .

[2]  Kenji Kurata,et al.  Role of reflection in light transmissivity of greenhouses , 1990 .

[3]  D. P. Giddens,et al.  Turbulence measurements in a constricted tube , 1980, Journal of Fluid Mechanics.

[4]  G.P.A. Bot,et al.  Developments in indoor sustainable plant production with emphasis on energy saving , 2001 .

[5]  T. Boulard,et al.  Measurement and prediction of solar radiation distribution in full-scale greenhouse tunnels , 2000 .

[6]  G. Raithby.  Discussion of the finite-volume method for radiation, and its application using 3D unstructured meshes , 1999 .

[7]  George Papadakis,et al.  Solar Radiation Transmissivity of a Single-Span Greenhouse through Measurements on Scale Models , 1998 .

[8]  G. Raithby,et al.  COMPUTATION OF RADIANT HEAT TRANSFER ON A NONORTHOGONAL MESH USING THE FINITE-VOLUME METHOD , 1993 .

[9]  Constantinos Kittas,et al.  Determination of the Spectral Properties of Several Greenhouse Cover Materials and Evaluation of Specific Parameters Related to Plant Response , 1998 .

[10]  Tadashi Takakura,et al.  Climate Under Cover: Digital Dynamic Simulation in Plant Bio-Engineering , 1993 .

[11]  O. Pironneau,et al.  Analysis of the K-epsilon turbulence model , 1994 .

[12]  Shaojin Wang,et al.  Experimental and numerical studies on the heterogeneity of crop transpiration in a plastic tunnel , 2002 .

[13]  S. Singer,et al.  Principles of environmental physics (contemporary biology series): by John L. Monteith. 241 pages, diagrams, 512 × 812 in. New York, American Elsevier Publishing Co., 1973. Price, $20.00. , 1975 .

[14]  M. Modest.  Radiative heat transfer , 1993 .

[15]  Chia-Jung Hsu.  Numerical Heat Transfer and Fluid Flow , 1981 .

[16]  Joel H. Ferziger,et al.  Computational methods for fluid dynamics , 1996 .

[17]  J. Monteith.  Climate and the efficiency of crop production in Britain , 1977 .

[18]  H. F. DeZwart.  Determination of Direct Transmission of a Multispan Greenhouse Using Vector Algebra , 1993 .

[19]  S. R. Mathur,et al.  Finite Volume Method for Radiative Heat Transfer Using Unstructured Meshes , 1998 .

[20]  Dennis N. Assanis,et al.  Evaluation of various high-order-accuracy schemes with and without flux limiters , 1993 .

[21]  Jan Pieters,et al.  Performances of Greenhouses with the Presence of Condensation on Cladding Materials , 1997 .

[22]  William A. Beckman,et al.  Solar Engineering of Thermal Processes, 2nd ed. , 1994 .

[23]  I. V. Pollet,et al.  Solar energy availability in greenhouses as affected by condensation on cladding materials , 1999 .

[24]  B. Launder,et al.  Lectures in mathematical models of turbulence , 1972 .

[25]  K. E. Cockshull,et al.  The influence of shading on yield of glasshouse tomatoes , 1992 .

[26]  D. Critten.  A REVIEW OF THE LIGHT TRANSMISSION INTO GREENHOUSE CROPS , 1993 .

[27]  G. Whitham.  Research in Applied Mathematics. , 1988 .

[28]  D. Gray,et al.  The validity of the boussinesq approximation for liquids and gases , 1976 .

[29]  Kang Y. Huh,et al.  A new angular discretization scheme of the finite volume method for 3-D radiative heat transfer in absorbing, emitting and anisotropically scattering media , 2000 .

[30]  Merril Eisenbud,et al.  Principles of Environmental Physics.John L. Monteith , 1975 .

[31]  Diego L. Valera,et al.  A Wind Tunnel Study of Airflow through Horticultural Crops: Determination of the Drag Coefficient , 2006 .

[32]  Thierry Boulard,et al.  Analysis of Greenhouse Ventilation Efficiency based on Computational Fluid Dynamics , 2006 .

[33]  W. Beckman,et al.  Solar Engineering of Thermal Processes , 1985 .

[34]  K. Kurata,et al.  Optimal shapes of parallel East-West oriented single-span tunnels with respect to direct light transmissivity , 1991 .

[35]  Thierry Boulard,et al.  Effect of Vent Arrangement on Windward Ventilation of a Tunnel Greenhouse , 2004 .

[36]  G. D. Raithby,et al.  A Finite-Volume Method for Predicting a Radiant Heat Transfer in Enclosures With Participating Media , 1990 .

[37]  Thierry Boulard,et al.  Optimisation of Greenhouse Insect Screening with Computational Fluid Dynamics , 2006 .