THERMAL-HYDRAULIC PERFORMANCE ANALYSIS OF FLUID FLOW IN TUBE WITH HELICAL SCREW INSERTS IN TRANSITION FLOW

An experimental analysis is arranged to evaluate thermal hydraulic performance analysis on fluid flow in helical screw inserts in tube with number of strips and different twist ratios in Transition flow regime. Single strip insert is also compared with double strip inserts of helical screw inserts with three values of twist ratios. Heat transfer enhancement is achieved with fluid flow in double strip as compared to single strip helical screw insert at decreases values of twist ratios and increases values of Reynolds number (Re). Maximum enhancement in the value of Nusselt number is achieved with double strip inserts at low value of twist ratio and Reynolds number as compared to Single strip inserts. Common correlations of Nusselt number and friction factor are generated. Thermal performance factor (TPF) is achieved maximum values with double strip insert at all flow rates at 2.5 of twist ratio than single strip inserts. Double strip inserts show suitability of helical screw insert in heat exchangers to compact the size of thermal applications.