Flow resistance of viscoelastic flows in fibrous porous media

Abstract

In this work, we present flow simulations of viscoelastic (Oldroyd-B and Leonov) fluids in the unidirectional fibrous porous media to investigate effects of the elasticity on the flow resistance. Extensive numerical simulations were carried out for the Oldroyd-B and Leonov fluids to investigate the flow resistance in some typical geometries of unidirectional fibrous porous media: square, hexagonal, as well as randomly aligned arrays of unidirectional fibers. To the best knowledge of the authors, we report for the first time the stiff increase of flow resistance through numerical simulations above a certain Weissenberg number. Considerable growth in the flow resistance has turned out to be closely associated with microstructure of porous media through the extensional stretch of polymers. For the hexagonal and randomly aligned fibers, where there are enough spaces behind fibers, significant amount of polymer stretch is observed along with substantial growth of the corresponding flow resistance. On the other hand, only minor change in flow resistance and negligible polymer stretch are observed in case of square-packing porous media. (C) 2017 Elsevier B.V. All rights reserved.