https://doi.org/10.1140/epjp/s13360-020-00339-2
Regular Article
Two immiscible stratified fluids with one nanofluid layer in a horizontal annulus
School of Mathematics and Physics, University of Science and Technology Beijing, Beijing, 100083, China
* e-mail: libotong@ustb.edu.cn
Received:
2
December
2019
Accepted:
17
March
2020
Published online:
30
March
2020
In this study, we investigate the motion of two immiscible stratified fluids in a two-dimensional horizontal annulus. The fluid flow system, including an upper Newtonian fluid layer and a lower nanofluid layer of different densities, is driven by gravitational forces at low Reynolds numbers. When the initial interface of the two fluids tends to be horizontal, the flow is slow and the time evolution of the fluid flow is depicted numerically. We paid special attention to the concentration of nanoparticles in the nanofluid and the influence of asymmetrical initial fluid distribution on the evolution of the flow. Depending on the initial distribution, the domain either expands or shrinks, and we develop different numerical techniques for each of them. The results can be useful to provide a controllable technique for the desirable equilibrium distribution of two immiscible fluids in a horizontal annulus, when the initial distribution and the nanofluid concentration are manageable.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature, 2020
