PIV measurements of slow flow of a viscoelastic fluid within a porous medium

• Published in: Experiments in fluids Vol. 51; no. 3; pp. 801 - 809
• Main Authors: Yip, Ronnie, James, David F., Currie, Iain G.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.09.2011; Springer
• Subjects: Arrays; Columns (structural); Cylinders; Deborah number; Engineering; Engineering Fluid Dynamics; Engineering Thermodynamics; Exact sciences and technology; Flows through porous media; Fluid dynamics; Fluid flow; Fluid- and Aerodynamics; Fluids; Fundamental areas of phenomenology (including applications); Heat and Mass Transfer; Instrumentation for fluid dynamics; Laminar flows; Low-reynolds-number (creeping) flows; Non-newtonian fluid flows; Nonhomogeneous flows; Physics; Pressure loss; Research Article; Particle Image Velocimetry Measurement; Solid Volume Fraction; Newtonian Fluid; Particle Tracking Velocimetry; Particle Image Velocimetry; Viscoelastic fluid; Porous medium flow; Particle image velocimetry; Slow flow; Pressure measurement; Experimental study; Velocity measurement; Cylinder set; Periodic structures
• ISSN: 0723-4864; 1432-1114
• DOI: 10.1007/s00348-011-1107-1

Particle image velocimetry (PIV) and pressure loss measurements were used to investigate slow flow through a square array of cylinders having a solid fraction of 10%. The test fluids were a Newtonian fluid and a Boger fluid, both of high viscosity such that the Reynolds number did not exceed 0.1. The pressure loss data reveal that the onset of elastic effects occurred at a Deborah number around 0.5 and that flow resistance was up to several times Newtonian values at Deborah numbers up to 3. PIV showed that the transverse velocity profiles for the Newtonian and non-Newtonian fluid were the same at Deborah numbers below onset. Above onset, the profiles became skewed, increasingly so as the Deborah number increased. In the wake regions between cylinders in a column, periodic flow structures formed in the spanwise direction. The structures were staggered from column to column, consistent with the skewing and were offset. These flow patterns are the result of an apparent elastic instability.