On Hydrodynamic Stability of Poiseuille and Couette Flows of Nanofluids in the Channel Between Concentric Cylinders

Abstract

A study is made of the hydrodynamic stability of Poiseuille and Couette flows of nanofluids in the channel formed by concentric cylinders. The influence of the concentration and size of silica nanoparticles in ethylene glycol on stability characteristics is considered. The concentrations of the nanoparticles ranges from 0 to 5%, and their size, from 10 to 210 nm. Neutral-stability curves have been constructed; the most unstable modes of perturbations have been found, and their increments have been studied. It has been shown that the action of the nanoparticles is destabilizing in all cases. The higher the concentration of the nanoparticles and the smaller the size of them, the larger the degree of this destabilization. Here, the critical Reynolds numbers decrease substantially and the spectrum of unstable perturbations changes.