Título: Journal of Fluid MechanicsImportada do Authenticus Pesquisar Publicações da Revista

Vol. 712

Páginas: 203-218

ISSN: 0022-1120

Editora: Cambridge University Press

ISI Web of Knowledge - 41 Citações

ISI Web of Science

Scopus - 56 Citações

FOS: Ciências da engenharia e tecnologias > Engenharia mecânica

ID Authenticus: P-002-2DB

DOI: 10.1017/jfm.2012.411

Abstract (EN): A combined experimental, numerical and theoretical investigation of the geometric scaling of the onset of a purely elastic flow instability in serpentine channels is presented. Good qualitative agreement is obtained between experiments, using dilute solutions of flexible polymers in microfluidic devices, and three-dimensional numerical simulations using the upper-convected Maxwell model. The results are confirmed by a simple theoretical analysis, based on the dimensionless criterion proposed by Pakdel & McKinley (Phys. R e v.Lett., vol. 77, 1996, pp. 2459-2462) for onset of a purely elastic flow instability. Three-dimensional simulations show that the instability is primarily driven by the curvature of the streamlines induced by the flow geometry and not due to the weak secondary flow in the azimuthal direction. In addition, the simulations also reveal that the instability is time-dependent and that the flow oscillates with a well-defined period and amplitude close to the onset of the supercritical instability.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 16