Proceedings of the 7th World Congress on Mechanical, Chemical, and Material Engineering (MCM'21)
Prague, Czech Republic – August, 2021
Paper No. HTFF 111
DOI: 10.11159/htff21.111

Numerical Model of Convective Heat Transfer in a Multi-level
Hydroponic Greenhouse
Vitaly Haslavsky1, Helena Vitoshkin2
1

Azrieli College of Engineering
26 Yaakov Shreibom Street, Jerusalem, Israel
vitaliha@jce.ac.il
2Agricultural Research Organization, The Volcani Center
P.O.Box 6, 5025001, 68 Dereh Hamacabim, Rishon lesion, Israel
elenav@volcani.agri.gov.il

Extended Abstract
Plant growth in a multi-level controlled environment allows intensive cultivation with minimal use of soil and water
resources. It also reduces the risks of yield losses, as it is not affected by climate change. However, multi-level plant factories
have not been widely utilized due to high energy consumption and complex design. The comprehensive review of greenhouse
ventilation methods [1] pointed out the impact of vent configuration on internal climatic conditions and crop growthinteractions. The importance of considering the microclimate at the leaf level as distinct from the overall indoor climate whenmanaging the greenhouse climate for disease control was also demonstrated by [2-4]. Effective interaction between plants
and the environment involves controlling temperature gradients, transpiration, carbon dioxide concentrations, and inner air
velocity and velocity within the leaf boundary-layer [5]. Therefore, structural design and microclimate analysis are needed
to improve air and temperature uniform distribution.
The numerical model has been developed to analyze the airflow characteristics and temperature distribution within amulti-level hydroponic grow system. The aim is to provide a uniform internal microclimate, evaluate the energy consumptionof the system, and to examine options for the use of renewable energy in a controlled environment. Three-dimensional flow
inside and around the multi-level unit has been modeled using ANSYS Software to explore the optimal structure elements
and ventilation methods. The numerical modeling of environmental conditions between the levels includes models ofturbulent forced airflow, transpiration rate, and convective heat transfer. The model of the porosity of a crop leaf layer andtranspiration rates, validated by experimental measurements conducted in a commercial greenhouse. The numericalsimulations describe flow regimes and temperature fields on each level. The model allows examination of the artificial
lighting intensity and the effect of supplemental solar radiation on the temperature in a greenhouse.

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