SIMULATION OF MICROCLIMATE IN A SLOPING GREENHOUSE USING CFD

The applicability of the CFD model for the sloping greenhouse was examined at high temperature and humidity in Japan.
A commercial CFD software FLUENT 6.2 and pre-processor program GAMBIT 2.0 were used in this study.
In order to consider the influence of crops on the greenhouse microclimate, the energy and water vapour source terms from the crops were calculated and dynamically loaded with the solver by user defined functions (UDFs) written using the C programming language.
The CFD model was validated using five measured data sets including the boundary conditions and the internal air temperatures taken at 16 points, which were obtained on August 1, 7, and 9, 2006. The results of the simulation showed that the inclusion of the energy balance of the tomato crops improved the accuracy of the calculation from 2.0 K to 1.6 K of the root mean square error (RMSE), under conditions where the wind velocities were within the range of 0.65 to 0.81 m/s.
The comparison also indicated that the internal air temperature at the lower part of the greenhouse was slightly overestimated; however, the temperatures at the upper part agreed with the measurement.
There were also qualitative agreements of the location where higher air temperatures appeared in the greenhouse.

International Symposium on High Technology for Greenhouse System Management: Greensys2007

T. Kuroyanagi, Y. Nagasaki, Y. Nakamoto, H. Tanaka, T. Ibuki

natural ventilation, energy balance, tomato, transpiration

https://doi.org/10.17660/ActaHortic.2008.801.107