A Numerical Study on the Thermal Performance of a Solar Air Heater Depending on the Hole Configuration and Geometry in the Absorber Plate

A series of numerical analyses was conducted to predict the thermal performance of a solar air heater depending on the hole configuration and geometry in the absorber plate. The planar dimensions of the prototype were 1 m (W) by 1.6 m (H), and the maximum air flow considered was 187 m/h. It was considered that protruding holes with a triangular opening in the absorber plate would invoke turbulence in the air flow to enhance the convection heat transfer. Six different hole configurations were investigated and compared with each other, while the hole opening height was considered as a design variable. Three-dimensional transient analyses were performed with a commercial software package on the airflow and heat transfer in the model. The numerical results were analyzed and compared from the view point of the outlet air temperature and its time response to derive the optimal hole pattern and hole opening height.