International Journal of Scientific Research and Engineering Development

This study presents the design, fabrication, and experimental investigation of an evacuated tube solar air collector integrated with loose-fit perforated twisted tape inserts to enhance thermo-hydraulic performance. Experiments were conducted under steady-state conditions by varying mass flow rates and tape geometries. Results showed a significant enhancement in heat transfer due to induced swirl flow and turbulence. The Nusselt number increased by 70–94% compared to a plain tube, with optimal performance at a twist ratio (y/D) of 2 and hole ratio (d/D) of 0.0714. However, an increase in friction factor was observed due to higher flow resistance. The maximum thermal performance factor reached 1.27, indicating overall system improvement. The system demonstrates strong potential for solar thermal applications such as air heating and agricultural drying.

S Ram Kumar, Vishnudas K K, Rizwin Ahammed, Rameez Raja, Tomin Saby Vadakkan,"Thermo-Hydraulic Performance Enhancement of Evacuated Tube Solar Air Collector Using Loose-Fit Perforated Twisted Tape Inserts" International Journal of Scientific Research and Engineering Development, V9(2): Page(1536-1537) Mar-Apr 2026. ISSN: 2581-7175. www.ijsred.com. Published by Scientific and Academic Research Publishing.