Heat transfer and mixing enhancement by Poiseuille-Taylor-Couette flow between two rotating elliptically-deformed annular tubes

Abstract

Multifunctional heat exchangers (HEX) are very important devices which are used in many industrial applications (aerospace, aeronautics, automobile, process and chemical engineering, etc). Improving their designs for an optimal overall performance is still a wide window for both research and development. In the present contribution, a new HEX design is proposed as two concentric elliptically-deformed tubes of complex geometry. Employing advanced computational fluid dynamics (CFD), we show how a combined Poiseuille-Taylor-Couette (PTC) analogous flow between two rotating concentric elliptically-deformed annular tubes, can efficiently enhance heat and mass transfer at low to medium Reynolds numbers (Re≤488). Furthermore, we illustrate how chaotic advection can be controlled by regulating the local flow inertia and rotational forces imposed by a combined flow between: i- Poiseuille flow, and ii- Taylor-Couette analogous flow that is generated by interchanging the clockwise/anticlockwise rotation of the inner and outer walls. Results are presented and discussed using Lagrangian tracking and Poincaré sections techniques that describe the different underlying physical phenomena of mixing and heat transfer.