Fully-Developed Flow in a Furrowed Wavy Channel: Characterization of Unsteady Flow Regimes and Its Effect on Thermal-Hydraulic Performance

Numerical study is done at various Reynolds numbers (100-2000), for periodically fully developed flow and heat transfer in five geometrically different wavy channels. Time signal analysis is done to distinguish various unsteady flow regimes and a flow regime map is proposed; demarcating steady, two types of periodic as well as quasi-periodic, and chaotic flow regimes. Temporal variation of flow structure and Nusselt number as well as friction factor are presented - in the various unsteady regimes - and discussed for a unified cause-and-effect study. Effect of different flow regimes on the thermal-hydraulic performance of wavy as compared to plane channel is presented. Effect of Prandtl numbers (0.01-100) is also studied.