Breaking axi-symmetry in stenotic flow lowers the critical transition Reynolds number

The critical layer in pipe flow at high Reynolds number.

We report the computation of a family of travelling wave solutions of pipe flow up to Re=75000. As in all lower branch solutions, streaks and rolls feature prominently in these solutions. For large Re, these solutions develop a critical layer away from the wall. Although the solutions are linearly unstable, the two unstable eigenvalues approach 0 as Re-->infinity at rates given by Re-0.41 and R...

Effect of the Reynolds Number on the Flow Pattern in a Stenotic Right Coronary Artery

It is well known that the Reynolds number has a significant effect on the blood flow in human arteries. We developed a three dimensional model with simplified geometry for a diseased right coronary artery segment to study the influence of the Reynolds number on the flow pattern in a stenotic coronary artery. Computations were carried out under physiological flow conditions to examine how the ch...

Linearized pipe flow to Reynolds number 107

A Fourier–Chebyshev Petrov–Galerkin spectral method is described for high-accuracy computation of linearized dynamics for flow in an infinite circular pipe. Our code is unusual in being based on solenoidal velocity variables and in being written in MATLAB. Systematic studies are presented of the dependence of eigenvalues, transient growth factors, and other quantities on the axial and azimuthal...

Effect of Reynolds Number in the Turbulent-flow Range

Does molecular rotation affect the transition Reynolds number?

We examine recent claims that the molecular rotation, which manifests itself in the form of bulk viscosity, has a measurable effect on the transition Reynolds number in pipe flow. We also conduct new experiments using argon. We conclude that the effects, if they exist at all, are negligibly small for the conditions of the experiment. @ 1998 Elsevier Science B.V.