@Article{, title={The Improvement of The Solar Air Heater Duct by Wired Ribs Utilization}, author={Osamah Raad skheel/alkhafaji}, journal={Karbala International Journal of Modern Science مجلة كربلاء العالمية للعلوم الحديثة}, volume={5}, number={3}, pages={163-170}, year={2019}, abstract={Abstract Heat transfer coefficient of the solar air heater duct (SAH) is low due increasing the thermal performance of its absorber. The present study tends to enhance the thermal characteristics of the SAH by adopting the wired ribs on the absorber under different ribs dimensions and arrangements. A rectangular duct is used to form the SAH with length L=1500mm, width w=100mm and height H=30mm. The used heat fluxes over the absorber are 1000W/m2 and 500W/m2 while the operated Reynolds number range is 708 ~ 6375. The utilized wired ribs are arranged over the absorber so as to develop a relative roughness height value (e/D = 0.043) in which generates a relative roughness pitch values of (P/e = 5, 10, 15). Moreover, another arrangement for the wired ribs develops a relative roughness height value (e/D = 0.086) that correspond the relative roughness pitch values of (P/e = 10, 20, 30). The results show an improvement in the average values of the Nusselt number with 9.34 % when e/D = 0.043 and heat flux of 500W/m 2 against the smooth absorber. It is also found that the average values of Nusselt number is improved with 5.31% when e/D=0.043 and heat flux = 1000W/m2.

} }