https://doi.org/10.26706/ijaefea.4.8.20211204

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Abstract:-

Enhancement of convective heat transfer using artificial roughness has gained significant attention for improving the performance of compact heat exchangers. In the present study, an experimental investigation is carried out to evaluate the influence of rib inclination on thermal performance in a rectangular duct. Circular and triangular ribs inclined at 45° are employed to analyze their effect on heat transfer characteristics under identical operating conditions. Experiments are conducted for air velocities ranging from 4 to 4.3 m/s, and the performance is evaluated in terms of heat transfer coefficient, Nusselt number, and heat transfer rate. The results reveal a substantial improvement in thermal performance for inclined rib configurations compared to the smooth duct. The heat transfer coefficient increases by approximately 240% to 255% for circular ribs and 280% to 300% for triangular ribs. Similarly, the Nusselt number shows an enhancement of about 240% to 250% for circular ribs and 280% to 295% for triangular ribs. The heat transfer rate is also significantly improved, with an increase of nearly 92% to 122% for circular ribs and 125% to 166% for triangular ribs relative to the smooth duct. The superior performance of inclined ribs is attributed to the generation of strong secondary flow, streamwise vortices, and improved fluid mixing along the rib direction. The study demonstrates that rib inclination plays a critical role in enhancing convective heat transfer, and among the tested configurations, triangular ribs at 45° orientation provide the highest thermal performance.

Index Terms:-

Experimental Investigation of Heat Transfer Enhancement in a Rectangular Duct Using Inclined Circular and Triangular Ribs at 45⁰ Orientation

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