The effect of polymer extensibility on crossflow of polymer solutions through cylinder arrays

Flow of wormlike micelle solutions through a periodic array of cylinders

“…The constant value of strain is due to the decrease in residence time as the Deborah number and extension rate are increased. These results are in good agreement with those reported by Chmielewski et al [64] where they argue that in the wake of a cylinder, nominal strains of ε = 3 can be built up. At a Deborah number of De = 4.5, where the CTAB-NaSal solutions become unstable an extension rate ofε = 0.21 s −1 , or equivalently at an extensional number of De ext = ε = 1.2, present in the wake of the cylinder.…”

“…In our geometry the shearing might therefore reduce the effect of strain hardening and increase the susceptibility of these fluids to elastic instabilities resulting from the breakdown of those wormlike micelle solutions in the strong extensional flow present in the wake of the circular cylinders. These findings are in good agreement with Chmielewski et al [64] who also found the flows of polymer solutions past cylinders to be unstable above a critical Deborah number.…”

Boger Fluids

“…Because sidewalls have much less influence with an array, one can create a nearly uniform flow, and Boger fluids have made it possible to distinguish the onset and magnitude of elastic effects. Experiments from two laboratories clearly show that (a) elasticity causes the pressure drop or flow resistance to rise, not dip, starting at a Weissenberg number of the order of unity and (b) flow resistance increases with We and can be an order of magnitude greater than that for Newtonian fluids (Chmielewski & Jayaraman 1992, Chmielewski et al 1990b, Khomami & Moreno 1997. The fluids in these studies were typical PIB-PB solutions, and the findings are similar to those found earlier for aqueous dragreducing fluids in packed beds of spheres (Durst & Haas 1981, James & McLaren 1975.…”

The conundrum of migraine headaches in the presence of patent foramen ovale

“…For a more correct derivation, additional terms have to be taken into account since the fluid is also exposed to elongational forces when it passes through the porous media matrix. Chmielewski et al141–143 investigated the elastic behavior of polyisobutylene solutions flowing through arrays of cylinders with various geometries. They recognized that the converging‐diverging geometry of the pores in porous media causes an extensional flow component that may be associated with the increased flow resistance for viscoelastic liquids.…”

“…The phenomena studied include polymer/tracer dispersion, excluded volume effects, polymer adsorption, and viscous fingering. Cannella et al61 experimentally investigated the flow of Xanthan solutions through Berea sandstone and carbonate cores in the presence and absence of residual oil. They used modified power‐law and Carreau rheologies in their theoretical analysis. Chmielewski et al141–143 conducted experiments to investigate the elastic behavior of the flow of polyisobutylene solutions through arrays of cylinders with various geometries. Chhabra and Srinivas161 conducted experimental work investigating the flow of power‐law liquids through beds of non‐spherical particles using the Ergun equation to correlate the resulting values of friction factor. They used beds of three different types of packing materials (two sizes of Raschig rings and one size of gravel chips) as porous media and solutions of carboxymethylcellulose as shear‐thinning liquids. Fletcher et al162 investigated the flow of biopolymer solutions of Flocon 4800MXC, Xanthan CH‐100‐23, and scleroglucan through Berea and Clashach cores utilizing Carreau rheological model to characterize the fluids. Hejri et al163 investigated the rheological behavior of biopolymer solutions of Flocon 4800MX characterized by power‐law in sand pack cores. Sabiri and Comiti164 investigated the flow of non‐Newtonian purely viscous fluids through packed beds of spherical particles, long cylinders and very flat plates.…”