Simulation and validation of the effect of horizontal and radial airflow on the microclimate of single-span greenhouses using CFD

Abstract

Greenhouse technology provides a controlled environment that optimizes crop production, especially under adverse conditions. Ventilation systems are essential for regulating the microclimate, affecting temperature, humidity, and gas exchange. This study evaluated the effectiveness of horizontal airflow (HAF) and radial airflow (RAF) fans in managing microclimate conditions within single-span greenhouses, utilizing Computational Fluid Dynamics (CFD) simulations for simulation while the data from the field experiment was used to validation. Temperature and relative humidity were collected from sensors positioned at various points within the greenhouses. The results indicated that RAF-GH maintained a higher mean temperature (14.88 °C) than HAF-GH (12.87 °C), leading to a more stable thermal environment conducive to crop growth. Additionally, RAF-GH exhibited higher consistent relative humidity levels, averaging 83.95 %, while HAF-GH recorded 74.94 %. CFD simulations revealed that RAF systems achieved more uniform temperature and humidity distributions than HAF systems, thereby offering a better environmental control. The simulations closely mirrored field experiment, confirming the accuracy and reliability of CFD modeling in predicting greenhouse conditions. The study concludes that RAF systems are more effective than HAF systems for maintaining optimal greenhouse conditions.