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פותח על ידי קלירמאש פתרונות בע"מ -
Numerical model of the three-dimensional isothermal flow patterns and mass fluxes in a pitched-roof greenhouse
Year:
2004
Authors :
ארבל, אברהם
;
.
שקליאר, אלכסנדר
;
.
Volume :
92
Co-Authors:
Shklyar, A., Agricultural Research Organization, The Volcani Center, Inst. of Agricultural Engineering, P.O. Box 6, Bet Dagan 50250, Israel
Arbel, A., Agricultural Research Organization, The Volcani Center, Inst. of Agricultural Engineering, P.O. Box 6, Bet Dagan 50250, Israel
Facilitators :
From page:
1039
To page:
1059
(
Total pages:
21
)
Abstract:
The three-dimensional isothermal flow patterns and mass fluxes in a full-scale, pitched-roof, single-span greenhouse were numerically resolved, and data from tests on a full scale were used to validate the code, the inlet boundary conditions and the greenhouse design grid method. For numerical solution of turbulent flow, a high-Reynolds-number k-ε model is suitable. Computational domain sizes were selected so as to fulfil the requirements of free-stream conditions whilst ensuring that grid geometrical characteristics satisfy the physical limitations of the standard k-ε model. A special feature of a case of a wind blowing parallel to a ridge (0°) is that the flow in the leeward half of the greenhouse comprises two vortexes with opposite senses of rotation, which bring in air mass through the vents and deliver it to the windward half. A spiral type of flow was found for winds blowing at 15-75° to the ridge direction: part of the air enters via the windward wall vent near the leeward gable-wall and emerges through the leeward roof vent near the windward gable-wall. Mass fluxes and flow patterns on wind direction, and on the opening angles of the windward and leeward vents. Thus, the ventilation rate induced by a wind directed perpendicularly to the greenhouse ridge is 4-4.9 times as great as that induced by a wind parallel to the ridge. A ventilation rate of a simulated greenhouse type was found to be significantly less responsive to a change in wind direction from 45° to 90° than to one from 0° to 45°. Present numerical results are in good agreement with those of other experiments and observations. © 2004 Elsevier Ltd. All rights reserved.
Note:
Related Files :
Computational fluid dynamic
Flow patterns
greenhouse
greenhouses
Ventilation
עוד תגיות
תוכן קשור
More details
DOI :
10.1016/j.jweia.2004.05.008
Article number:
0
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
20980
Last updated date:
02/03/2022 17:27
Creation date:
16/04/2018 23:40
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Scientific Publication
Numerical model of the three-dimensional isothermal flow patterns and mass fluxes in a pitched-roof greenhouse
92
Shklyar, A., Agricultural Research Organization, The Volcani Center, Inst. of Agricultural Engineering, P.O. Box 6, Bet Dagan 50250, Israel
Arbel, A., Agricultural Research Organization, The Volcani Center, Inst. of Agricultural Engineering, P.O. Box 6, Bet Dagan 50250, Israel
Numerical model of the three-dimensional isothermal flow patterns and mass fluxes in a pitched-roof greenhouse
The three-dimensional isothermal flow patterns and mass fluxes in a full-scale, pitched-roof, single-span greenhouse were numerically resolved, and data from tests on a full scale were used to validate the code, the inlet boundary conditions and the greenhouse design grid method. For numerical solution of turbulent flow, a high-Reynolds-number k-ε model is suitable. Computational domain sizes were selected so as to fulfil the requirements of free-stream conditions whilst ensuring that grid geometrical characteristics satisfy the physical limitations of the standard k-ε model. A special feature of a case of a wind blowing parallel to a ridge (0°) is that the flow in the leeward half of the greenhouse comprises two vortexes with opposite senses of rotation, which bring in air mass through the vents and deliver it to the windward half. A spiral type of flow was found for winds blowing at 15-75° to the ridge direction: part of the air enters via the windward wall vent near the leeward gable-wall and emerges through the leeward roof vent near the windward gable-wall. Mass fluxes and flow patterns on wind direction, and on the opening angles of the windward and leeward vents. Thus, the ventilation rate induced by a wind directed perpendicularly to the greenhouse ridge is 4-4.9 times as great as that induced by a wind parallel to the ridge. A ventilation rate of a simulated greenhouse type was found to be significantly less responsive to a change in wind direction from 45° to 90° than to one from 0° to 45°. Present numerical results are in good agreement with those of other experiments and observations. © 2004 Elsevier Ltd. All rights reserved.
Scientific Publication
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