93 and cut depth w = 0.5cm are compared with experimental simulated data on helical twist tape [21] as shown in Figures Figures1212 and and13.13. It is found that the VCT offered an additional heat transfer Imatinib order enhancement with less friction factor.Figure 8Simulated Nusselt number of V-cut twisted tape with different twist ratios (y) and different cut depths.Figure 9Simulated friction factor of V-cut twisted tape with different twist ratios (y) and different cut depths.Figure 10Simulated Nusselt number of classical and V-cut twisted tape inserts (y = 2.93) with cut depth w = 0.5cm.Figure 11Simulated friction factor of classical and V-cut twisted tape inserts (y = 2.93) with cut depth w = 0.5cm.Figure 12Simulated Nusselt number of V-cut twisted tape and RLT inserts.

Figure 13Simulated friction factor of V-cut twisted tape and RLT inserts.8. ConclusionCFD simulation for the heat transfer augmentation transfer and friction factor in a circular tube fitted with classical and V-cut twisted tape inserts with y = 2.93, 3.91, and 4.89 and cut depth w = 0.5, 1, and 1.5cm in laminar flow conditions has been reported using FLUENT version 6.3.26. The results are concluded as follows.The values of the Nusselt number and friction factor for the tube with V-cut twisted tape are noticeably higher than the values for the plain tube and tube equipped with classical twisted tapes as well. Over the range of the Reynolds numbers considered, the tube equipped with the V-cut twisted tape y = 2.93 and w = 0.5cm offered supreme heat transfer enhancement than the classical twisted tapes and other V-cut twisted tapes used.

The simulated data for V-cut twisted tape y = 2.93 and w = 0.5cm is compared with theoretical and experimental work of Right-left helical tape inserts (RLT) with twist ratio y = 2.93 at the same conditions. The results show that the proposed model of V-cut twisted tape offered 107% heat transfer enhancement with less friction factor. This configuration can be AV-951 used for heat transfer augmentation. AcknowledgmentsThe authors wish to especially acknowledge the financial assistance (FRGS/1/2013/TK07/UKM/01/1) offered by the University Kebangsaan Malaysia and MOSTI for carrying of this investigation.