Experimental and Numerical Study of Optimization of Perforated Ribs Geometry and Configuration Using Taguchi Approach

The present experimental and computational investigation considers the optimization of solar air heaters (SAHs) with perforated ribs to simultaneously enhance the Nusselt number (Nu) and minimize pressure losses. This study introduces a novel approach by utilizing the Taguchi method to optimize geometric parameters, enabling efficient evaluation of heat transfer and pressure drop interplay for improved solar air heater performance. The effects of relative rib height (e/D), rib pitch (p/e), perforation diameter (d/e), and the number of perforations (n) were investigated using the finite volume method. A three-dimensional, steady-state, symmetric, and turbulent flow based on the k−ω SST turbulence model was employed, with optimization conducted using the Taguchi method. The analysis was performed at a Reynolds number (Re) of 18,000. The complex influence of perforation geometry on heat transfer and flow characteristics underscores the challenge of balancing performance parameters. Larger perforation diameters and optimized rib spacing reduced pressure drops by weakening recirculation zones and promoting uniform flow, while also enhancing local heat transfer. The optimal configuration (e/D = 0.11, p/e = 20, d/e = 0.7, n = 2) achieved a 41% improvement in thermal-hydraulic performance. Increasing the perforation size (d/e) improved heat transfer up to a threshold of d/e = 0.7. Beyond this point, the turbulence intensity decreases and improvement in heat transfer ceases. The findings provide a practical framework for designing energy-efficient SAHs by systematically evaluating geometric parameters and offer new insights into balancing heat transfer and pressure loss, contributing to advancements in renewable energy and thermal management.