Evaluation of shear stresses of generalized Newtonian fluids in pore scale closure models
A new analytical expression for the gradient of the intrinsic phase average of the pressure in terms of the wall shear stresses is proposed. This expression is obtained by volume averaging of the governing equations and closure by means of the two dimensional RUC model (a pore-scale model for the analysis of fluid traversing a porous medium). One is the model for generalized Newtonian fluids traversing porous media and the other for fluid flowing through a two dimensional porous medium of which the interstitial channel widths may differ in size. The shear stresses in the interstitial channels of the RUC are evaluated by means of numerical simulations and compared to the fully developed velocity profile assumed in the RUC model. © 2008 American Institute of Physics.