Transition to turbulence in accelerating flows

This research was directed towards obtaining a simple laminar to turbulent transition criterion for non-periodic, unsteady flows. A novel parametric framework was formulated, enabling the derivation of a transition criterion based on maximum rate of entropy production. The qualitative features of the analysis proved to be satisfactory, in that it predicted increased stability for accelerating flows, and the converse result for decelerating flows. On the quantitative side, comparison with the limited experimental results available indicates that the criterion predicts the onset of turbulence at too low a Reynolds number. A modified form is presented in an attempt to overcome the problem.