Experimental Heat Transfer using Insert for Nusselt Number Enhancement

Abstract

Various heat transfer and its enhancement techniques are found in literature. Many researchers have focused on such topics typically in last decade of last century. The paper deals with experimental work of the passive techniques which do not require direct application of external power, whereas the active techniques require an. Exact method and system used for research from 1964 till around 2000 is presented. A case study of twisted tape of Y as 4.2 and 5.2. It is seen that overall heat transfer coefficient is a function of Reynolds number. .It is noticed that on the tube side the flow conditions have included both laminar and turbulent flow. Graph presents shows heat transfer data for both twisted tapes. It can be seen that the overall heat transfer coefficient in general increase with increase in Reynolds number. For a given Reynolds number the overall heat transfer coefficient increase with decrease in twist ratio i.e. tape with tighter twist. Also friction factor increase with decreases in the twist ratio 1