Developing heat transfer and friction loss in an impingement jets solar air heater with multiple arc protrusion obstacles

The current study examines the augmentation of heat transfer and friction in a flow through impingement jets solar air heater with multiple protrusion arc obstacles. The experimental outcomes pertaining to relative height ratio (e(P)/d(P)) from 0.5 to 2.0, relative width ratio (W-P/W-AP) from 1.0 to 6.0, angle of arc (alpha(a)) from 35 degrees to 75 degrees, relative pitch ratio (P-P/e(P)) from 8.0 to 12 and for the constant data of stream wise variation (X-S/d(H)) = 0.433, span wise variation (Y-S/d(H)) = 0.866 and jet diameter ratio (D-J/d(H)) = 0.065 respectively. The influence of multi arcs protrusion obstacles has been studied for a Reynolds number varied from = 5000 to 19,000. The optimal improvement is achieved at W-P/W-AP 8 5.0, e(P)/d(P) = 1.0, P-P/e(P) = 9.5 and alpha(a) = 55 degrees. With the help of investigational values correlations for Nusselt number and friction factor are generated for solar air heater as a function of multiple arcs protrusion obstacles. The correlations were developed for Nu(rs) and f(rs) and a deviation from the experimental results was about +/- 9% and +/- 11%, respectively.