Please use this identifier to cite or link to this item: https://hdl.handle.net/10216/106718
Author(s): Simon J. Haward
Mónica S. N. Oliveira
Manuel A. Alves
Gareth H. McKinley
Title: Optimized Cross-Slot Flow Geometry for Microfluidic Extensional Rheometry
Issue Date: 2012
Abstract: A precision-machined cross-slot flow geometry with a shape that has been optimized by numerical simulation of the fluid kinematics is fabricated and used to measure the extensional viscosity of a dilute polymer solution. Full-field birefringence microscopy is used to monitor the evolution and growth of macromolecular anisotropy along the stagnation point streamline, and we observe the formation of a strong and uniform birefringent strand when the dimensionless flow strength exceeds a critical Weissenberg number Wi(crit) approximate to 0.5. Birefringence and bulk pressure drop measurements provide self-consistent estimates of the planar extensional viscosity of the fluid over a wide range of deformation rates (26 s(-1) <= (epsilon) over dot <= 435 s(-1)) and are also in close agreement with numerical simulations performed by using a finitely extensible nonlinear elastic dumbbell model.
Subject: Física
Physical sciences
Scientific areas: Ciências exactas e naturais::Física
Natural sciences::Physical sciences
URI: https://repositorio-aberto.up.pt/handle/10216/106718
Related Information: info:eu-repo/grantAgreement/FCT - Fundação para a Ciência e Tecnologia/Projectos de I&DT em Todos os Domínios Científicos/PTDC/EME-MFE/114322/2009/EXTENSION - Escoamento extensional de fluidos complexos em microcanais/EXTENSION
info:eu-repo/grantAgreement/FCT - Fundação para a Ciência e Tecnologia/Projectos de I&DT em Todos os Domínios Científicos/PTDC/EQU-FTT/118716/2010/Design de um "reómetro-num-chip" para o desenvolvimento de fluidos análogos ao sangue/RheoChip
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:FEUP - Artigo em Revista Científica Internacional

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