2021/07/20 by Mohd Bilal Khan, Khan, Mohd Bilal, C. Sasmal +1
Chemical Engineering · Chemistry · Engineering · #Rheology and Fluid Dynamics Studies #Surfactants and Colloidal Systems #Fluid Dynamics and Thin Films
paper · pdf · doi:10.48550/arxiv.2107.09453
The flow of viscoelastic wormlike micellar solutions (WLMs) in porous media\nis encountered in many practical applications like enhanced oil recovery or\ngroundwater remediation. To understand the flow dynamics of these complex\nfluids in porous media, a model porous media consisting of a straight\nmicrochannel with micropore throats present in it, is very often used. In this\nstudy, we perform an extensive numerical investigation to understand the flow\ndynamics of wormlike micellar solutions based on the two-species\nVasquez-Cook-McKinley (VCM) model for micelles through such model porous media.\nWe find the existence of an elastic instability once the Weissenberg number\nexceeds a critical value; likewise, it was seen in many prior experimental and\nnumerical studies dealing with polymer solutions. However, for the present case\nof a WLM solution, we observe that this elastic instability is greatly\ninfluenced by the breakage and reformation mechanisms of the wormlike micelles.\nIn particular, we notice that the intensity of this instability (characterized\nby the fluctuating flow fields) increases as the Weissenberg number increases;\nhowever, beyond a critical value of it, this elastic instability and/or the\nflow field fluctuation is suppressed because of the breakage of long micelles.\nThis is in contrast to the polymer solutions for which the flow field gradually\ntransits to a more chaotic and turbulent-like state (or the so-called elastic\nturbulence state) as the Weissenberg number gradually increases. Additionally,\nwe observe that the flow dynamics of these WLM solutions are strongly dependent\non the type of micropore throat, the number of pore throats, and the spacing\nbetween two consecutive pore throats. An extensive discussion on the pressure\ndrop and apparent viscosity is also presented in the present study.\n