Surface Instabilities on a Thin Power-Law Fluid During Spin Coating. (22nd May 2014)

• Record Type: Journal Article
• Authors: Chen, C.-I.; Lin, M.-C.; Chen, C.-K.
• Is Part Of: Journal of mechanics. Volume 30:Number 5(2014)
• Page Start: 505
• Page End: 513
• Publication Date: 2014-05-22
• Subjects: Nonlinear stability -- Power-law fluid -- Spin coating; Mechanics, Analytic -- Periodicals; Mechanics -- Periodicals; 620.1005
• DOI: 10.1017/jmech.2014.39
• Languages: English
• ISSNs: 1727-7191

Abstract

Abstract : The phenomena of surface instabilities in a thin power-law fluid during spin coating are investigated. The set of Navier-Stokes equations with non-Newtonian behavior in the region of low Reynolds number serves as a mathematical description of the physical systems. Long-wave perturbation analysis is proposed to derive an evolution equation of the Ostwald de-Waele type fluid to govern the propagation of surface waves. Weakly nonlinear dynamics of film flow is studied by the multiple scales method. The amplitude of instability is determined by a Ginzburg-Landau equation. The study reveals that the degree of power-law index plays a vital role in stabilizing the film flow. The shear-thinning fluid is more unstable than the shear-thickening fluid in the stability analysis. Further, the nonlinear wave speed in the supercritical stability region decreases with increasing values of power-law index.