INVESTIGATIONS ON HEAT TRANSFER IN WAVY CHANNELS USING FIELD SYNERGY PRINCIPLE
Wavy channels are known to be one of the passive method for heat transfer enhancement. Enhancement in heat transfer in wavy channel is achieved by breaking and destabilizing of the thermal boundary layer due to generation of streamwise and spanwise vortices. Geometry and shape of the channel play good role in determining strength of the vortices. Objective of the present work is to study the effect of different types of surface waviness in generation of vortices and its effect on heat transfer in wavy channels. Three-dimensional numerical investigations have been carried out for channels having three different surface waviness, viz. rectangular, triangular and sinusoidal, for a fixed Reynolds number (Re) of 3000. Inward as well as outward waviness in out-of-phase arrangement for the three shapes have been considered. In present study, the wave parameters such as wavelength, amplitude and channel height are kept fixed. Effect of secondary flow generated due to waviness on flow and heat transfer has been investigated with the help of secondary flow intensity and field synergy principle. Finally, effect of waviness on thermodynamic performance has been studied with the help of entropy generation analysis.