要約

We have previously shown that the response of turbulence in a transient channel flow is effectively a laminar-turbulent bypass transition. In that study, only one step-change flow between fixed initial and final Reynolds numbers was investigated. This paper reports a series of new simulations with a range of initial and final Reynolds numbers. All cases studied show characteristics of transition. The main effect of varying the Reynolds number can be attributed to the change of the 'free-stream' turbulence intensity and the critical equivalent Reynolds numbers of all cases are well correlated with a simple function of the initial turbulence intensity.