02139nas a2200157   4500008004100000022001400041245007800055210006900133260008700202300002700289490000700316520152700323100001701850700001801867856009601885       2016                        eng d  a1070-663100aFingering instability in the flow of a power-law fluid on a rotating disc0 aFingering instability in the flow of a powerlaw fluid on a rotat  a1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScJAN  aArticle Number: 0131020 v283 a<p>A computational study of the flow of a non-Newtonian power law fluid on a spinning disc is considered here. The main goal of this work is to examine the effect of non-Newtonian nature of the fluid on the flow development and associated contact line instability. The governing mass and momentum balance equations are simplified using the lubrication theory. The resulting model equation is a fourth order non-linear PDE which describes the spatial and temporal evolutions of film thickness. The movement of the contact line is modeled using a constant angle slip model. To solve this moving boundary problem, a numerical method is developed using a Galerkin/finite element method based approach. The numerical results show that the spreading rate of the fluid strongly depends on power law exponent n. It increases with the increase in the shear thinning character of the fluid (n &lt; 1) and decreases with the increase in shear thickening nature of the fluid (n &gt; 1). It is also observed that the capillary ridge becomes sharper with the value of n. In order to examine the stability of these ridges, a linear stability theory is also developed for these power law fluids. The dispersion relationship depicting the growth rate for a given wave number has been reported and compared for different power-law fluids. It is found that the growth rate of the instability decreases as the fluid becomes more shear thinning in nature, whereas it increases for more shear thickening fluids. (C) 2016 AIP Publishing LLC.</p>1 aArora, Akash1 aDoshi, Pankaj  uhttps://library.ncl.res.in/content/fingering-instability-flow-power-law-fluid-rotating-disc