Optimization of Roughness Parameter of Artificially Roughed Solar Air Heater

Solar air heaters are simple and cost-effective devices that harness freely available energy from the sun. However, their efficiency is limited by the low coefficient of heat of air. To improve their performance, many techniques have been applied, with one common approach being the use of artificially rough absorber plates. Nonetheless, designing the artificial roughness and selecting appropriate operating parameters to achieve higher heat transfer rates and lower friction factors can be quite challenging. In this study, the researchers aimed to optimize the roughness parameters and operating parameter to enhance the thermal performance of a solar air heater duct with artificially roughened surfaces. The Taguchi methodology was employed for this purpose. Through this approach, the researchers successfully identified the optimal roughness and operating parameters that lead to the desired performance levels. The operating parameter considered in the study was the Reynolds number, while the roughness parameters included Relative roughness height and Relative roughness pitch.