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פותח על ידי קלירמאש פתרונות בע"מ -
Aerodynamic properties of boundary layers along screens
Year:
2009
Source of publication :
Biosystems Engineering
Authors :
טנאי, יוסף
;
.
כהן, שבתאי
;
.
מולר, מרקוס
;
.
Volume :
102
Co-Authors:
Tanny, J., Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, Volcani Center, P.O.B. 6, Bet Dagan, 50250, Israel
Möller, M., Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, Volcani Center, P.O.B. 6, Bet Dagan, 50250, Israel
Cohen, S., Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, Volcani Center, P.O.B. 6, Bet Dagan, 50250, Israel
Facilitators :
From page:
171
To page:
179
(
Total pages:
9
)
Abstract:
Agricultural screens that cover crops modify the exchange of heat, mass and momentum between the crop and the atmosphere. The properties of the boundary layer above an insect-proof screenhouse, in which sweet pepper was grown, were investigated experimentally. A flat-roof screenhouse 110 m long, 60 m wide and 3.2 m high was used. Wind and temperature sensors were mounted above the screen 60 m to the east of the western edge of the house and 30 m north of its southern edge. Aerodynamic properties of the wind profile, namely the friction velocity, roughness length, zero-plane displacement and aerodynamic resistance were calculated and presented with respect to the stability of the surface layer above the screenhouse. It was shown that neutral and stable conditions, when compared with unstable conditions, act to inhibit turbulence, to reduce the roughness length, to displace the wind profile upwards to just above the screen, and to increase the aerodynamic resistance. The results were compared with previous data obtained for a small shading screen. Good qualitative similarity was obtained between the two sets of data and the causes of the quantitative differences between the two studies under unstable conditions were discussed. © 2008 IAgrE.
Note:
Related Files :
Boundary layer flow
Boundary layers
cover crops
Crops
Gas dynamics
Roughness lengths
עוד תגיות
תוכן קשור
More details
DOI :
10.1016/j.biosystemseng.2008.11.015
Article number:
0
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
24436
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:07
Scientific Publication
Aerodynamic properties of boundary layers along screens
102
Tanny, J., Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, Volcani Center, P.O.B. 6, Bet Dagan, 50250, Israel
Möller, M., Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, Volcani Center, P.O.B. 6, Bet Dagan, 50250, Israel
Cohen, S., Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, Volcani Center, P.O.B. 6, Bet Dagan, 50250, Israel
Aerodynamic properties of boundary layers along screens
Agricultural screens that cover crops modify the exchange of heat, mass and momentum between the crop and the atmosphere. The properties of the boundary layer above an insect-proof screenhouse, in which sweet pepper was grown, were investigated experimentally. A flat-roof screenhouse 110 m long, 60 m wide and 3.2 m high was used. Wind and temperature sensors were mounted above the screen 60 m to the east of the western edge of the house and 30 m north of its southern edge. Aerodynamic properties of the wind profile, namely the friction velocity, roughness length, zero-plane displacement and aerodynamic resistance were calculated and presented with respect to the stability of the surface layer above the screenhouse. It was shown that neutral and stable conditions, when compared with unstable conditions, act to inhibit turbulence, to reduce the roughness length, to displace the wind profile upwards to just above the screen, and to increase the aerodynamic resistance. The results were compared with previous data obtained for a small shading screen. Good qualitative similarity was obtained between the two sets of data and the causes of the quantitative differences between the two studies under unstable conditions were discussed. © 2008 IAgrE.
Scientific Publication
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