# Taylor–Couette flow
Taylor–Couette flow is the fluid between two concentric cylinders when one of them rotates. It is the most
studied [[Bifurcation_theory|bifurcation]] sequence in [[Fluid_dynamics]] because the geometry is simple, the
control parameter is a single knob, and the flow passes through a long, repeatable ladder of states on its way
to [[Turbulence]] — each transition sharp, each new pattern selected rather than imposed.
## The ladder
Turn slowly and the fluid shears smoothly in [[Laminar_flow]]. Past a threshold, centrifugal
[[Force]] destabilises the layer and it snaps into a stack of counter-rotating toroidal Taylor vortices, evenly
spaced along the axis. Turn faster and those vortices develop travelling waves, then modulated waves, then
chaotic states, then fully turbulent flow that still keeps the vortex stack visible inside it. That progression
is a textbook route to [[Chaos_theory|chaos]] and a working example of
[[Self-organization]] with a measurable onset — an experiment [[Dynamical_system|dynamical systems]] theory
can be checked against directly.
## Beyond the laboratory
The same instability sets a limit in any rotating machinery with an annular gap: bearing lubrication films,
electric-motor air gaps, and drilling annuli all pay a torque penalty once Taylor vortices appear. Taylor–
Couette reactors exploit the vortices instead, using them for gentle controlled mixing in
[[Chemical_engineering|bioprocess]] work where shear must stay low. Astrophysical accretion-disc stability is
argued in the same terms, and the [[Laminar_flow]] unmixing demonstration uses this very apparatus.
**Microsim brief (next pass):** Annulus seen in cross-section with a rotation-rate slider; the flow snaps into stacked vortices at the threshold, then wavy, then chaotic. State name printed as it changes.
**On the spine:** [[Laminar_flow]] · [[Turbulence]] · [[Vortex]] · [[Rayleigh–Bénard_convection]] · [[Bifurcation_theory]] · [[WT!Thury_Hydrodynamics_Compendium]].
## Wikipedia : Wikitube
**Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Taylor–Couette_flow) : [Wikitube](https://en.wikitube.io/wiki/Taylor–Couette_flow)
## Previous hub tags
Hubs: `Life_Physics`, `Systems`. Portals: [[PORTAL_WT!Thury_Hydrodynamics_Compendium]], [[PORTAL_Physics]], [[PORTAL_Dynamical_system]], [[PORTAL_Self-organization]].
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*Fluid seed wave · 2026-09-10 · seed register · microsim layer pending.*