Heat Transfer Augmentation using Twisted Tapes

The present review describes progress with the passive augmentation techniques in the recent past and will be useful to designers implementing passive augmentation techniques in heat exchangers. In the past decade, several studies on the passive techniques of heat transfer augmentation have been reported. Passive heat transfer augmentation methods do not require any direct input of external power; rather they use it from the system itself which ultimately leads to an increase in fluid pressure drop. Twisted tape inserts are a significant approach for improving the heat transfer properties of a heat exchanger without impacting the overall performance of the system in the passive technique. The following review is divided into two sections: heat transfer enhancement in laminar flow and heat transfer enhancement in a turbulent flow.