Flow patterns of the fully developed pulsatile flow in a curved pipe.

Abstract

The fully developed periodic laminar flows of incompressible Newtonian fluid through a pipe of circular cross section which is coiled in a circle have been simulated numerically. The flow patterns are characterized by three parameters: the Womersley number Wo, the amplitude ratio β, and the Dean number De. The effect of these parameters on the flow has been studied for the range 15.07≤De≤265.49, 2.l9≤Wo≤50.00, and 0.50≤β≤2.00 for the curvature ratio, δ, equal to 0.05. The mannner in which the secondary flows evolve with increasing Womersley number and Dean number is explained. The secondary flow patterns are classified into three groups : the viscous-term-dominated type, the convection-term-dominated type, and the inertia-term-dominated type. It is found that, when the amplitude ratio of the volumetric flow rate, prescribed by a cosine function, is equal to 1.0, 4 - 6 vortices of the secondary flow appear at high Dean number, and that the Lyne-type flow patterns disappear at β≥0.50.