Numerical investigation of CFD parameters: Evaluating height variations on microclimate and crop performance in large-scale soilless greenhouses in northern Tunisia

This paper examines the climate conditions of a soilless greenhouse using numerical modeling and experimental setups. The objective is to predict the impacts of design parameters on the microclimate, focusing on adjusting the roof height of the soilless tunnel greenhouse in Tunisia. Numerical simulations using the ANSYS FLUENT 16.2 software were employed to account for the dynamic impacts of current tomato and basil crops on airflow and heat exchanges. An experimental study on a prototype soilless greenhouse in Tunis-Manouba validated the proposed Computational Fluid Dynamics model. This research also investigates how changes in greenhouse height affect the flow characteristics and energy dynamics, recommending optimal climate conditions for soilless agriculture. Developed correlations express the average air temperature and air velocity inside the greenhouse as functions of the height and the ambient temperature. Additionally, reducing the greenhouse height by about 35 % can increase the average temperature inside the greenhouse by 2 K. These findings provide valuable insights for designing efficient greenhouses, improving energy management, and optimizing crop yields. The study also establishes relationships between temperature, Vapor Pressure Deficit, meteorological conditions, and roof height, contributing to sustainable agriculture practices and climate-resilient farming.