Heat Transfer Analysis of a Finned Solar Air Heater

Abstract

A theoretical method is presented for the investigation of a reflective fin solar air heater. The heat transfer processes include radiation in both the solar and IR spectra, mixed convection (forced and natural) in the air and conduction in the fins. The governing equations have been solved numerically to obtain the velocity and temperature fields in the developing and developed flow regions. The efficiency of the finned structure is then calculated, and the results of a parametric study are shown. It has been found that natural convection effects are significant and strong buoyancy leads to separation and reversed flow. The efficiency increases with lower surface emissivity and lower thermal conductivity of the fins.