Author : R. S. Kalase, S. S. Uttarwar, S.D. Kathwate and N.T. Dhokane

Heat transfer enhancement techniques as passive, active or a combination of passive and active methods are
commonly used in areas such as process industries, heating and cooling in evaporators, thermal power plants, airconditioning equipment, refrigerators, radiators for space vehicles, automobiles (in tracked vehicle it plays very
important roll), etc. Passive techniques, where inserts, extended surfaces like fins of various shapes and sizes are used in the flow passage to enhance the heat transfer rate, are benefited compared with active techniques, because the insert manufacturing process is easier and it can be easily applied in an existing heat exchanger. In design of compact heat exchangers, passive techniques can play an important role if a proper passive configuration/combinations can be selected according to the heat exchanger working condition (both flow and heat transfer conditions). Ribs, fins, dimples, Vortices etc., are the most commonly passive heat transfer enhancement devices. In this paper, major emphasis is given to work with different shapes of fins, and their arrangement because, these are found effective heat transfer enhancement tools.

Keywords: Heat transfer enhancement, Rectangular Offset Serrated Plate Fins, Wavy fins, Pressure Drop, Ejector
cooling, rating method.