THE EFFECTS OF PLANT ARRANGEMENT ON AIRFLOW CHARACTERISTICS IN A NATURALLY VENTILATED GLASSHOUSE

S. Sase
Measurements were made of the internal air velocity on different row directions. The rows of tomato plants were arranged perpendicular to the side walls in the south compartment of a twin-span glasshouse with continuous hinged side and ridge ventilators, while the rows in the north compartment were arranged parallel to the side walls. The plant density was 1.85 plants per square meter in both compartments. The tomato plants were topped at a height of approximately 2 m above the ground before the measurements. The internal velocity was measured continuously with a hot-wire anemometer which was connected with a microcomputer-based data acquisition system.

Comparisons were made of velocity coefficients which are defined as the ratio of internal air velocity to external wind velocity. An example of the results indicates that the velocity coefficient for the rows perpendicular to the side walls depended on wind direction and increased up to 0.4 when wind direction shifted to E, i.e., perpendicular to the side walls. On the other hand, the velocity coefficient for the rows parallel to the side walls was almost constant and ranged from approximately 0.1 to 0.2. The average velocity coefficients were determined when the angles of all ventilators were 50°, and were found to be greater for the rows perpendicular to the side walls than those for the rows parallel to the side walls in all wind directions, especially in a wind direction of E. The reason is discussed in terms of the airflow pattern in the glasshouse. When only the ridge ventilators were opened at an angle of 50°, it was found that the velocity coefficient depended neither on row direction nor wind direction, and its average was 0.12.

Sase, S. (1989). THE EFFECTS OF PLANT ARRANGEMENT ON AIRFLOW CHARACTERISTICS IN A NATURALLY VENTILATED GLASSHOUSE. Acta Hortic. 245, 429-435
DOI: 10.17660/ActaHortic.1989.245.57
https://doi.org/10.17660/ActaHortic.1989.245.57

Acta Horticulturae