Enhancing climate control and management in arid conditions: A numerical study on the impact of roof pitch angle on greenhouse climates

Abstract

This paper presents a comprehensive investigation of the impact of the roof pitch angle on the microclimate in greenhouses, particularly in arid regions. The research combines experimental datasets with numerical modeling. The numerical model aims to assess the collective effects on the internal environment involving crops, soil, polyethylene, and air. Validation of numerical outcomes is conducted through a comparison with experimental data, with a specific focus on the temperature and velocity profiles derived from a greenhouse prototype. The study incorporates numerical model optimization, encompassing a turbulence model selection and a grid independence analysis, to ensure the reliability of the numerical model. The numerical results demonstrate that the roof pitch angle significantly affects the distributions of the interior temperature, the velocity fields, the Discrete Ordinates (DO) irradiation, and the static pressure. To accurately capture such variations, robust correlations were established. In addition, a comparative analysis of the crop height (Hc) impact was carried out demonstrating the direct effect of the height on both velocity and temperature profiles. In fact, at a Hc of 1 m, the temperature reaches T = 321.5 K, whereas for Hc = 0.5 m, the temperature does not exceed T = 318 K. This finding holds significant implications for the greenhouse design and the agricultural operations, advancing our understanding of the intricate dynamics that govern the microclimate within greenhouses, especially in arid regions. The findings of this work provide valuable insights into the impact of the roof pitch as well as the crop height on greenhouse climates and underscores the importance of precise modeling and control for successful agricultural management.