Abstract
Crop production in all climatic conditions has been a vital requirement leading to the implementation of greenhouse systems. The microclimate of these greenhouse systems plays an essential role in the survival of the crops. Conducting testing in real-life greenhouses can be expensive and cause disruptions to the daily processes. This research focuses on the investigation of the microclimate of a naturally ventilated commercial greenhouse by experimental and numerical means. The experimental testing consists of a reduced scale model tested inside a wind tunnel at various scenarios. Temperature measurements are taken through AD590 temperature sensors connected to a data acquisition hardware tool called CDAQ 978 and these temperature values are recorded through Matlab. A Testo 425 anemometer is used to measure the velocity at various points of the roof vents of the greenhouse model. Incense sticks are used to produce smoke within the greenhouse model and these smoke particles are visualised using laser sheets. A numerical model is created for the experimental testing scenario of roof vents being opened, side vents being closed, and heating plates switched on at a temperature of 30℃ and 50 % wind tunnel power. Two physics conditions are created for the numerical model, one for the fluid (air) and one for the solid (Perspex). The numerical model is validated by comparison of temperature values with experimental values at the same points in the greenhouse. The values obtained are similar showing the same trend. It is also found that the side vents being closed do not impact the temperature values close to the floor to a large extent when there is change in velocity of the flow towards the greenhouse observed.