Heat transfer augmentation for the flow of a viscous liquid in circular tubes using twisted tape inserts

Heat transfer enhancement for laminar flow in tubes using curved delta wing vortex generator inserts

“…Manglik & Bergles [11] and Agrawal & Raja Rao [15]. The comparison was found to be within the limits of uncertainties, as shown in Fig.…”

Heat Transfer in an Axially Rotating Tube Fitted with twin Twisted Tapes

“…(11) is lower than the smooth-wall value of 0.8 (17) , the relative enhancement in heat transfer falls when the Reynolds number increases. The reduced heat transfer augmentation as Re increases has also been found in the swirl tube fitted with single twisted tape (14), (18) . Equation (11) is taken as the reference datum for subsequent comparison of the rotational effect on heat transfer.…”

Studies on heat transfer and friction factor characteristics of turbulent flow through a micro-finned tube fitted with left–right inserts

“…A comparison between Micro-finned tube with twisted tape inserts, lefteright inserts and plain tube flow is usually made by comparing heat transfer coefficients at same pumping power, since this is relevant to the operation cost. For equal pumping power VDP plain ¼ VDP microþtt or microþLÀR (14) and the relationship between friction and Reynolds number can be expressed as: f Re 3 plain ¼ f Re 3 microþtt or microþLÀR (15) The performance ratio based on constant pumping power is the ratio of the convective heat transfer coefficient of the Micro-finned tube with the twisted tape inserts, lefteright inserts to the plain tube which can be written as follows:…”

“…Chakroun and Al-Fahed [13] studied the effect of twisted tape width on both heat transfer and pressure drop for fully developed flow. Agarwal and Raja Rao [14] reported laminar twisted tape generated swirl flow in a circular tube.…”