Convective transfers mainly determine the energy and mass balances which regulate the micro-climate inside a greenhouse. Air flow and temperature patterns induced by natural ventilation through greenhouse roof openings are only considered here. Flow visualizations were performed on a half scale test cell simulating the absorption of solar radiation at the floor surface of a single-span greenhouse. Temperature and air flow patterns were observed in a steady regime i) with a single sided roof vent and ii) with two symmetrical one. An air inflow always take place at the lower part of the openings and feed a single convective loop which follows the walls of the greenhouse before escaping through the upper part of the vents. These natural convective patterns were numerically simulated by means of a Computational Fluid Dynamic code (CFD 2000TM). It was found that the convective cell, velocity values and the temperature profiles were generally in good agreement with the experimental results.
Greenhouse natural ventilation by buoyancy forces.
EPIC '98, Volume 2, pp 522-527