Transition to turbulence in Taylor Couette flow

Transition to turbulence in Taylor Couette flow

Alidai, A.

Westerweel, J. (mentor)
Delfos, R. (mentor)

Mechanical, Maritime and Materials Engineering

Mechanical Engineering

Solid and Fluid Mechanics

2011-08-25

The most recent studies of intermittent state in linearly stable shear flows, like pipe, Plane Couette and Taylor Couette flow, have shown that turbulent structures, created by finite-amplitude perturbation, have an exponential distribution of the lifetimes. Here we experimentally examine the lifetime of turbulent spot in Taylor Couette flow (with stationary inner cylinder) for different perturbation mechanisms and different boundary conditions. We show that for all of these cases, the decay of the turbulent spot can be described by Poisson process, which supports the chaotic transient model for this flow. Furthermore, we show that characteristic lifetime of the turbulent spot increases with Reynolds number faster than exponentially, but does not diverge to infinity. This is in agreement with the most recent studies in pipe and Taylor Couette flows and implies that turbulence is a transient state for all Reynolds numbers (before the global bifurcation). Finally, we show that there is a universal behavior for the characteristic lifetime of the intermittent state in Taylor Couette flow with stationary inner cylinder. This universal series is obtained using critical Reynolds number and aspect ratio as scaling parameters.

Turbulence
Taylor Couette
Transition

http://resolver.tudelft.nl/uuid:cbc316b7-d807-4f68-b4b2-b8a980b5c7be

2011-09-28

Student theses

master thesis

(c) 2011 Alidai, A.