Optimization of Thermohydraulic Parameters in Solar Air Heater Ducts Featuring I‐Shaped Ribs
Hasan Abdulkadim Abbas Alhilali, Kadhim K. Idan Al‐Chlaihawi, Ahmed Kadhim Zarzoor, Mujtaba A. Flayyih
Abstract
ABSTRACT Solar air heaters (SAHs) are among the most useful devices for collecting solar energy and utilizing it for heating purposes. The primary aim of this endeavor is to enhance the performance of SAH. This is accomplished by artificially roughening the surface of the absorber using ribs. A two‐dimensional computational fluid dynamics study looks at how a novel I‐shaped ribs affect hydraulic and thermal performance in the SAH channel was carried out. The re‐normalisation group turbulence model is utilized for numerical simulation, and its accuracy is evaluated against proven correlations and literature findings. Various discrete rib parameters, such as pitch ratio ( range 7.14–17.86) and relative width ratio ( range 0.5–1), have been optimized for the Reynolds number () range of 6000–21,000, considering a fixed value of relative roughness height () of 0.042. The main findings for the SAH are presented in terms of the Nusselt number (), the friction factor (), the thermal–hydraulic performance parameter (THPP), and the visualization of various fluid characteristics. The results demonstrate that compared with a smooth SAH duct, the current rib geometries significantly improve heat transmission and fluid mixing, boosting by 2.498–2.978 times and by 2.812–4.393 times. The study determined the optimal rib characteristics of and . This combination achieved a peak THPP of 2.014. A generalized correlation has been established for Nu and using the numerically projected results.