Numerical and experimental analysis of convective heat transfer in a heated greenhouse

Abstract

Internal convective flows, resulted from buoyancy forces, in a greenhouse tunnel were numerically and experimentally analysed and discussed. Experiments were performed in an experimental arc type tunnel greenhouse with a tomato crop, which was heated by a network of heating pipes or by an air heater or by their combination according to the outside climate conditions. A three dimensional (3D) sonic anemometer and fast response sensors for air temperature and humidity were used in order to map climate variables in different locations inside the greenhouse. For the numerical part of the study a commercially available computational fluid dynamics code was used A 3D model was built and average values form experimental data were used for boundary conditions. The crop was modelled by means of the concept of porous medium approach. In general a good quantitative and qualitative agreement was found between experimental and numerical results. Results highlight the influence of heating system on greenhouse microclimate.