Abstract
Varieties of heat transfer enhancement techniques developed by different researchers. Heat transfer augmentation techniques refer to different methods used to increase rate of heat transfer and basically divided into active, passive and compound heat transfer enhancement technique. Use of twisted tape is one such promising passive heat transfer augmentation technique. In this work a novel design of twisted tape is introduced. An attempt has been made to analyze the effect of newly designed twisted tape on heat transfer enhancement using computational Fluid Dynamics (CFD) Techniques. Physical time and energy considered for experimentation will be more so in present work simulation has been carried out using ANSYS FLUENT software to find performance of novel twisted tape. The tape considered here is corrugated twisted tape in which corrugations are given longitudinally with fixed angle of corrugation then it is twisted. Comparison in performance of tube without tape, with plain twisted tape and twisted corrugated tape has been done. Verification of model has been done using available correlations for plain tube and tube with plain twisted tape. Range of Reynolds varied from 10,000 to 60,000. Heat transfer and pressure drop characteristics studied using computational analysis. Nusselt Number and friction factor of round tube with CTT insert is found to be 1.79–1.94 times and 2.5–3.5 times higher respectively compared to round tube without any insert. Thermal performance factor chosen as performance evaluation criteria keeping pumping power constant. Performance of tube with corrugated twisted tape insert found to be better than plain tube (improvement in TPF up to 31%) taking into account both heat transfer and friction factor.
Performance evaluation of tube-in-tube heat exchangers with heat transfer enhancement in the annulus