화학공학소재연구정보센터
Journal of Non-Newtonian Fluid Mechanics, Vol.165, No.19-20, 1309-1327, 2010
Cross-stream forces and velocities of fixed and freely suspended particles in viscoelastic Poiseuille flow: Perturbation and numerical analyses
The cross-stream migration of a circular particles (or infinitely long cylinder) in two dimensional, inertialess viscoelastic pressure-driven flows is examined through complementary finite element simulations and second-order fluid perturbation analyses for small Deborah number (De), where De is defined as the fluid relaxation time divided by the characteristic flow time. A neutrally buoyant, freely suspended particle migrates toward the center of the channel for all particle sizes and cross-stream positions due to the coupled effects of the linear and quadratic variations of the imposed velocity. A particle that is held at a fixed position, in contrast, experiences a cross-stream force directed toward the wall as a result of the coupled effects of the local shear flow and the flow relative to the particle. (C) 2010 Elsevier B.V. All rights reserved.