WJM  Vol.2 No.4 , August 2012
Computational Fluid Dynamics Analysis of Greenhouses with Artificial Heat Tube
ABSTRACT
With the workmanship decrease in farms, the necessity to rationalize the use of other inputs and the development of technology has rapidly expanded the use of computer simulation in agricultural systems. One of the agricultural systems in which the modeling process of plant growth has been more engaged is the greenhouse production for horticultural crops. In Mediterranean climate, it is during the night that the energy losses are important and can be compensated with an artificial heat input. In this work an experiment was performed in a greenhouse in the north of Portugal. Temperature values in several points and air velocity in the aperture were measured during the night for three different cases: natural convective heating (case A); artificial heating tubes (AHT) (case B); AHT and natural ventilation (case C). A CFD simulation, carried out using FLOTRAN module of ANSYS, was also performed in two-dimensional configuration to obtain the indoor air temperature and velocity fields for the three cases. A very good agreement between experimental and numerical temperature values were verified, which allows to validate the adopted numerical procedure. In case A, the average temperature was 2.2℃. An average increase of 6.7℃ and 3.5℃ on the air temperature was obtained for the case B and case C, respectively. These results clearly emphasis the influence of each thermal load on greenhouse indoor air properties.

Cite this paper
nullN. Couto, A. Rouboa, E. Monteiro and J. Viera, "Computational Fluid Dynamics Analysis of Greenhouses with Artificial Heat Tube," World Journal of Mechanics, Vol. 2 No. 4, 2012, pp. 181-187. doi: 10.4236/wjm.2012.24022.
References
[1]   I. Seginer, “Optimal Control of the Greenhouse Environment: An Overview,” Acta Horticulturae, Vol. 406, 1996 pp. 191-201.

[2]   O. Korner and H. Chala, “Design for Improved Temperature Integration Concept in Greenhouse Cultivation,” Computers and Electronics in Agriculture, Vol. 39, No. 1, 2003, pp. 39-59. doi:10.1016/S0168-1699(03)00006-1

[3]   T. Boulard, and B. Draoui, “Calibration and Validation of a Greenhouse Climate Control Model,” Acta Horticulturae, Vol. 406, 1996, pp. 49-61.

[4]   B. J. Bailey and W. Day, “The Use of Models in Greenhouse Environmental Control,” Acta Horticulturae, Vol. 491, 1999, pp. 93-99.

[5]   T. Boulard and S. Wang, “Experimental and Numerical Studies on the Heterogeneity of Crop Transpiration in a Plastic Tunnel,” Computers and Electronics in Agriculture, Vol. 34, No. 1-3, 2002, pp. 173-190. doi:10.1016/S0168-1699(01)00186-7

[6]   S. Wang and T. Boulard, “Measurement and Modelling of Radioactive Heterogeneity in a Greenhouse Tunnel,” Acta Horticulturae, Vol. 534, 2000, pp. 139-146.

[7]   S. Wang and J. Deltour, “Theoritical Study of Natural Ventilation Flux in a Single Span Greenhouse,” Biotechnologie, Agronomie, Société et Environnement, Vol. 2, No. 4, 1998, pp. 256-263.

[8]   S. Wang, J. Pieters and J. Deltour “Studies on Radiometric, Thermal and Climatic Properties of a New Greenhouse Covering Materials,” Acta Horticulturae, Vol. 491, 1998, pp. 324-333.

[9]   J. J. Costa, L. A. Oliveira and D. Blay, “Test of Several Versions for the K-E Type Turbulence Modelling of Internal Mixed Convection Flows,” International Journal of Heat and Mass Transfer, Vol. 42, No. 23, 1999, pp. 43914409. doi:10.1016/S0017-9310(99)00075-7

[10]   J. H. Ferziger and M. Peri?, “Computational Methods for Fluid Dynamics,” 2nd Edition, Springer Verlag, New York, 1999. doi:10.1007/978-3-642-98037-4

[11]   J. C. Tannehill, D. A. Anderson and R. H. Pletcher, “Computational Fluid Mechanics and Heat Transfer,” 2nd Edition, Taylor & Francis Ltd., Oxfordshire, 1997.

[12]   B. J. Bailey, “Optimal Control of Dioxide Enrichment in Ventilated Greenhouses. Workshop on Management,” Identification and Control of Agriculture Buildings, Universidade de Trás-os-Montes e Alto Douro, Vila Real, 1998, pp. 1-15.

 
 
Top