Title of article :
A review of greenhouse engineering developments during the 1990s
Author/Authors :
D.L Critten، نويسنده , , B.J Bailey، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2002
Pages :
22
From page :
1
To page :
22
Abstract :
The paper begins with a brief review of earlier work. The 1990s saw limited extensions to the theory, computer modelling and practices relating to light transmission, apart from an interesting, but unproven new design to improve transmission. Studies concentrated on improving the performance of greenhouse elements (e.g. cladding), including methods of measurement. Thermal studies show significant progress. Computer modelling was extended to include the time dimension and finite element techniques were used to improve resolution of detail. As with light transmission, studies intended to improve the quality of greenhouse elements were also carried out. Understanding and modelling the performance of a thermal screen has also been improved, both as such and as an integral part of the greenhouse. Much effort was directed towards understanding ventilation. Analysis has shown that different sources exist (thermal-, wind-induced), and these have been analysed. The existence of internal circulating air patterns has also been established. The optimisation of carbon dioxide concentrations in greenhouses has now reached the point where the gain to a grower can be readily predicted. Further computer modelling of light transmission to include the effects of scattering and modelling of skylight to predict leaf irradiance are proposed. Extension of finite element techniques to further improve resolution in thermal studies is recommended. A comprehensive investigation of the physical and engineering aspects of ventilation and internal air flows is also needed, to support the extended thermal studies of the greenhouse. Finally, a pilot study, anticipating the design of a computer-controlled greenhouse is envisaged.
Keywords :
Sky radiance , Sunlight , Heat transfer coefficient , Temperature , Wind conditions , Water uptake , CO2
Journal title :
Agricultural and Forest Meteorology
Serial Year :
2002
Journal title :
Agricultural and Forest Meteorology
Record number :
959148
Link To Document :
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