Effects of staggered dimple array under different flow conditions for enhancing cooling performance of solar systems

Enhancing cooling performance of internal channel with dimple array is promising technology for various solar energy systems. In this study, we investigate the use of dimple arrays within these coolant channels as a means of achieving higher cooling performance while minimizing pressure loss. Experiments were conducted to evaluate the effects of dimple arrays under various flow conditions (laminar, transition, and turbulent). Flow measurements revealed that the dimple array promotes secondary flows and turbulent intensity, particularly under transitional flow conditions. Among the tested flow conditions, the highest thermal performance ratio of 1.8 was achieved at Re_H = 2000 and 3000 (transition flow cases), resulting in a 47% increase in heat transfer compared to the laminar flow case (Re_H = 1000). These results suggest that dimple arrays with transitional flow conditions could be an effective means of improving the cooling performance of solar energy systems and ultimately contribute to reducing carbon dioxide emissions and preventing climate change. Further research is needed to optimize the dimple array design for specific flow conditions cooling applications for solar energy systems.