An Experimental Evaluation of Thermal Stratification in a Fan-Ventilated Greenhouse
| Autor: | S. Li, D.H. Willits |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Hydrology
Canopy Airflow Biomedical Engineering Soil Science Greenhouse Forestry Thermal stratification Atmospheric sciences Physics::Geophysics Reduced properties Computer Science::Computational Engineering Finance and Science Air temperature Astrophysics::Solar and Stellar Astrophysics Area ratio Environmental science Agronomy and Crop Science Physics::Atmospheric and Oceanic Physics Food Science Evaporative cooler |
| Zdroj: | Transactions of the ASABE. 51:1443-1448 |
| ISSN: | 2151-0040 |
| DOI: | 10.13031/2013.25237 |
| Popis: | Experiments were performed to investigate air velocity and vertical air temperature distributions in a fan-ventilated greenhouse. The effects of ventilation rate and canopy size on the allocation of airflow between canopy and non-canopy areas were examined. The data suggested that the ratio of the air velocity within the canopy to the mean velocity of the entire greenhouse cross-section depended on not only the area ratio of canopy to greenhouse cross-section, but also ventilation rate. The ratio of canopy air velocity to greenhouse average velocity decreased if ventilation rate increased. The effects of outside solar radiation, ventilation rate, evaporative cooling pads, and presence of a canopy on the vertical air temperature variations were also investigated. The vertical air temperature variation increased approximately linearly with solar radiation. Use of an evaporative pad increased the temperature variation. Increasing ventilation rate resulted in reduced air temperature variation. The presence of a canopy modified the vertical temperature distribution and reduced temperature variations as well. |
| Databáze: | OpenAIRE |
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