In this investigation, thermo-hydraulic performance of rectangular ducts roughened with a new configuration of ‘V-down rib having gap’ on one wide wall is determined. Small symmetrical gap equal to rib height is created at the centre of both legs of V of continuous V-down rib. The duct has...

This paper presents thermo-hydraulic performance comparison of rib roughness under investigation, ‘V-down ribs with gap’ and similar reported rib roughness geometries used in solar air heater duct. The present rib roughness has flow-attack-angle and relative roughness height of 60° and...