CREEPING FLOW-THROUGH SINUSOIDALLY CONSTRICTED CAPILLARIES

The steady pressure-driven flow of an incompressible Newtonian fluid t hrough an axisymmetric capillary whose diameter varies sinusoidally in the axial direction is studied numerically under conditions of neglig ible inertial effects. The boundary integral formulation is used to ob tain detailed velocity and pressure distributions within the capillary , and to determine the effects of amplitude and wavelength of corrugat ion on the kinematic structure of the flow. In particular, the critica l values of the geometric parameters leading to flow reversal within t he expansion region of the capillary are established. The dependence o f the pressure drop through the capillary on the geometric parameters is also discussed with reference to the predictions of various effecti ve pore models. (C) 1995 American Institute of Physics.