Author: In-Bok LEE1*, H. SHORT2, Sadanori SASE1, Limi OKUSHIMA1, and Guo Yu QIU1
Abstract
Natural ventilation system modifications were evaluated using a computational fluid dynamics
(CFD) numerical model (code: Fluent Version 4.5). Wind speed and direction, side vent opening
size and location, roof vent opening type, and number of spans were examined in terms of
ventilation rates and airflow distribution. For the side vent located at 2.5 m above the floor with a
west wind of 2.5 m/s, 59 % of the incoming air through the side vent was predicted to move out
through the first roof vent opening without reaching distant areas in the greenhouse, resulting in
high inside air temperatures. The air mainly moved in through the side vent and fourth roof vent
openings for an east wind of 0.5 m/s while the third and fourth roof openings were the only
predicted inlets of airflow for an east wind of 2.5 m/s. The hinged open roof multi-span
greenhouses were predicted to have significantly higher natural ventilation rates than the double
polyethylene-covered multi-span greenhouses for all the spans in the absence of side vent.
Keywords: computational fluid dynamics(CFD)
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https://www.researchgate.net/profile/I-B_Lee/publication/289530353_Evaluation_of_Structural_Characteristics_of_Naturally_Ventilated_Multi-Span_Greenhouses_Using_Computer_Simulation/links/58411a7408ae61f75dd09e3e/Evaluation-of-Structural-Characteristics-of-Naturally-Ventilated-Multi-Span-Greenhouses-Using-Computer-Simulation.pdf