Extensional flow of polymer solutions through the porous media
[ 1 ] Instytut Technologii i Inżynierii Chemicznej, Wydział Technologii Chemicznej, Politechnika Poznańska | [ P ] employee
2018
chapter in monograph / paper
english
EN The flow through porous media plays an important role within several areas of science. In many real processes in which the channels undergo continuous expansion and contraction, fluids are subjected not only to shearing but also to stretching. Such examples are the fluid flows through the plate heat exchangers, the porous beds and gaps of rock during crude oil extraction. Typically, pure and/or extensional flow is often required in many practical situations. Most often, we are dealing with the so-called mixed flow, where the deformation rates have parallel and perpendicular components to the flow direction. Solutions of high molecular weight polymers exhibit considerable differences in extensional and shear flow behaviors, and the ratio of extensional viscosity to shear viscosity can be as much as 100 times higher. In case of the flexible polymer solutions through porous media is the increase in flow resistance obtained beyond a critical flow rate. That increase has been attributed to the extensional nature of the flow field in the pores caused by the successive expansions and contractions. Such solutions exhibit strain hardening in extension. In case of the polymer solutions with semi-rigid and rigid chain structures, only the extent strain thinning region can be observed.
377 - 393
20
WoS (15)