American Society of Agricultural and Biological Engineers

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Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan

Citation:  Transactions of the ASAE. VOL. 41(3):833-836 . (doi: 10.13031/2013.17222) @1998
Authors:   M. Kacira, T. H. Short, R. R. Stowell
Keywords:   Sawtooth greenhouse, Natural ventilation, Computational fluid dynamics, Fluent, Greenhouse cooling

A computational fluid dynamics (CFD) program, Fluent V4, was used to predict natural ventilation rates and airflow patterns of a multi-span, sawtooth greenhouse for various roof and side vent openings and outside wind speeds. Predicted rates were found to be both well above and well below a standard volumetric air exchange rate of 1.0 A.C. min–1. The maximum and most acceptable ventilation rates were obtained with the combined use of a windward side vent and leeward roof vents on all multi-span sections. Ventilation rates ranged from 1.4 to 4.01 A.C. min–1 for the best two-span case and 0.14 to 2.0 A.C. min–1 for the similar four-span case for outside wind speeds of 0.5 and 2.0 m s–1, respectively. Predicted ventilation rates ranged from 0.17 to 0.7 A.C. min–1 when no side vent was used and the roof vents were fully open.

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