Since the seminal studies by Osborne Reynolds in the nineteenth century, pipe flow has
served as a primary prototype for investigating the transition to turbulence in wall-bounded …

In his landmark paper of 1883, Reynolds addressed the question of why the fluid motion
along a pipe changes from a laminar to a turbulent state at modest flow rates. His …

The route to turbulence in pipe flow is a complex, nonlinear, spatiotemporal process for
which an increasingly clear understanding has emerged in recent years. This paper …

Over a century of research into the origin of turbulence in wall-bounded shear flows has
resulted in a puzzling picture in which turbulence appears in a variety of different states …

A new theory of coherent structure in wall turbulence is presented. The theory is the first to
predict packets of hairpin vortices and other structure in turbulence, and their dynamics …

Although the equations governing fluid flow are well known, there are no analytical
expressions that describe the complexity of turbulent motion. A recent proposition is that in …

Transitional pipe flow is modeled as a one-dimensional excitable and bistable medium.
Models are presented in two variables, turbulence intensity and mean shear, that evolve …

We propose a general strategy for determining the minimal finite amplitude disturbance that
triggers transition to turbulence in shear flows. This involves constructing a variational …

The transition to turbulence in wall-bounded shear flows is typically subcritical, with a poorly
understood interplay between spatial fluctuations, pattern formation, and stochasticity near …

This paper describes an experimental study of the unforced laminar-to-turbulent transition in
pipe flow. Two pipes with different length-to-diameter ratios are investigated, and the …