THEORATICAL AND EXPERIMENTAL ANALYSIS OF SOLAR AIR HEATER WITH W-SHAPED ROUGHNESS ON ABSORBER PLATE.

Abstract

Analysis is made for Reynolds number of 18000 – 21000. The thermal performance is investigated for W – shaped roughness of thickness (t) 5mm, length of 10.5 cm, with an angle of 25°. The simulation is carried out using solar irradiance as heat input at the location of Amravati 20.93°N 77.75°E. Comparison of Reynolds no and Nusselt no is made. The thermal efficiency is found to increase as the temperature goes on increasing simultaneously the pressure at outlet is greater than inlet pressure. The mechanical power which is required is increased due to the roughness present on absorber plate. The heat transfer between smooth and roughened surface is compared. The experimental results are compared with analytical results on ANSYS 18.1. The thermal efficiency for the smooth surface is around 40 – 45% at particular temperature after roughening the absorber plate the efficiency increased upto 50 – 60% for the same temperature.