Theory 02/Fluid Dynamics

Turbulence Needs Strain Over Rotation

The claim

Transition to turbulence in rotating and stratified flow is set by the ratio of strain to rotation rather than by Reynolds number alone.

01The mechanism

Rotation suppresses the vortex stretching that sustains turbulence; when strain cannot overcome that suppression, the flow relaminarises at any Reynolds number.

02Predictions

P1Transition should occur at a critical strain-to-rotation ratio.
P2High Reynolds flows should stay laminar above the ratio.

03Refutation

Transition tracking Reynolds number regardless of rotation would remove the ratio.