Simulating Pulsatile Flows Through a Pipe Orifice by an Immersed-Boundary Method

Abstract

A pulsatile laminar flow of a viscous, incompressible fluid through a pipe with a sudden constriction (an orifice) was simulated by an immersed-boundary method. A fluid is forced to move by an imposed sinusoidally varying pressure difference, Δp(t). For a pulsatile flow through a pipe orifice, an oscillating recirculation bubble develops behind the orifice. The induced flow rate, Q(t), the recirculation bubble length, Lb(t), as well as their phase shift (ϕQ,ϕL) with respect to the imposed pressure difference were computed for different constriction ratios and the Womersley (Ws) number.