ISHS Acta Horticulturae 534: International Conference and British-Israeli Workshop on Greenhouse Techniques towards the 3rd Millennium
MEASUREMENT AND ANALYSIS OF AIR SPEED DISTRIBUTION IN A NATURALLY VENTILATED GREENHOUSE |
| Authors: | S. Wang, T. Boulard, R. Haxaire |
| Keywords: | Airflow, natural ventilation, greenhouse, wind effect, climate |
| Abstract:
Air speed distribution is a key factor influencing heat and mass transfer in greenhouses. The air speed profiles in the centre of a naturally ventilated greenhouse with a tomato crop were investigated by means of a customised multi-point two-dimensional sonic anemometer system. The experimental results showed that air speed was linearly dependent both on external wind speed and greenhouse ventilation flux. Under leakage ventilation, however, the air speed remained nearly constant at a low value (<0.1 m s-1), due to negligible wind and temperature effects on greenhouse air exchange rate. Based on the measured air speed profiles and ventilation flux, an estimation method for calculating the average internal air speed was established. This method can be applied to crop aerodynamic resistance calculations and irrigation management. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
