کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
670793 1459057 2012 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
From viscous fingering to elastic instabilities
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
From viscous fingering to elastic instabilities
چکیده انگلیسی

An analytical and numerical study of the linear Saffman–Taylor instability for a Maxwell viscoelastic fluid is presented. Results obtained in a rectangular Hele–Shaw cell are complemented by experiments in a circular cell corroborating the universality of our main result: The base flow becomes unstable and the propagating disturbances develop into crack-like features. The full hydrodynamics equations in a regime where viscoelasticity dominates show that perturbations to the pressure remain Laplacian. Darcy’s law is expressed as an infinite series in the cell thickness. An unique dimensionless parameter λ¯, equivalent to a relaxation time, controls the growth rate of the perturbation. λ¯ depends on the applied gradient of pressure, the surface tension, the cell thickness, and the elastic modulus of the fluid. For small values of λ¯, Newtonian behavior dominates whereas for higher values of λ¯ viscoelastic effects appear. For the critical value λ¯=λc¯≃10 a blowup is predicted and fracture-like patterns are observed.


► Viscoelasticity changes the most unstable wavenumber in Saffman–Taylor instability.
► A blow up occurs at large Deborah numbers.
► Fracture-like patterns are a consequence of viscoelasticity.
► New phenomena are expected in microfluidic devices.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Newtonian Fluid Mechanics - Volumes 173–174, April 2012, Pages 30–39
نویسندگان
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