Thermo-Hydraulic Performance Evaluation Using W-Discrete Rib in Solar Air Heater

Background/Objective: This paper have more emphasis towards augmentation of solar air duct thermal efficiency. Flow of heat restricted by sub-layer of laminar flow is the major criterion to reduce the thermal efficiency of solar air duct. Methods/Statistical Analysis: For breaking laminar sub-layer artificial roughness with pattern of W-Discrete geometry has been developed. With all consideration of different previous geometries as a pattern of artificial roughness W-Discrete ribs have best thermo-hydraulic performance. During experimental investigation different parameter taken are Reynolds number of 14000-4000, duct aspect ratio of 8, angle of attack of 45° and relative roughness height of 0.03375. Findings: Maximum increment of Nusselt number along with friction factor found in order of 2.79 and 1.98 as compare to smooth plate. Increase in heat transfer enhancement rate is obtained to be 2.35 times for W-discrete up and 2.60 times for W-discrete down rib pattern. Simultaneously with the consideration of smooth plate data results have been evaluated. Application/Improvements: Now a day's various solar collection and conversion systems are used like air heaters for crop drying, solar air conditioning and industrial applications. Solar collector is most important component that accounts for major portion of system cost comprising and utilization as a whole.