STUDY OF HEAT TRANSFER ON BROKEN ARC ROUGHNESS ELEMENTS ON THE ABSORBER PLATE FOR SOLAR ENERGY BASED HEATER: A REVIEW

Performance of solar air heater can be enhanced by adding roughness to the inner periphery. The present study on the effect of various shape parameters for broken arc roughness elements of heat transfer and friction factor characteristics of rectangular duct. The duct has Reynolds number (Re) range of 3000-22300, respective roughness height (e/D) values is 0.045, arc angle (α) is 60˚ and roughness width (W/w) is 5 and relatively roughness pitch is 8. The maximum enhancement in Nusselt number and friction factor is obtained by 6.74 and 6.73 times. The thermo hydraulic performance is obtained to be maximum for the relative broken width of 1.0 and relative broken position of 0.25.