Thermo-hydraulic performance of solar air heater having twisted rib over the absorber plate

Researchers are working to enhance the performance of the solar air heater through infusing various turbulators of different geometry and size over the absorber plate. The present work studied the effect of twisted rib over the absorber plate of solar air heater. Experimentations are performed varying roughness parameters such as relative roughness pitch (P/e) values of 6-10, rib inclination angle (α) in the range of 30°-90°, twist ratio (y/e) of 3-7 and Reynolds number in the range of 3500-21000, to acquire its influences on heat propagation rate and flow friction. The heat transfer and flow friction characteristic with this roughness are compared with a smooth surface for similar flowing conditions. The maximum enhancement for heat propagation characteristic and friction factor had been noticed to be 2.58 and 1.78 times that of smooth surface respectively. The thermo-hydraulic performance had been evaluated for the optimum range of roughness geometric parameters.