抄録
Turbulent flow near a wall is autonomously driven by coherent structures. By sudden disappearance of these structures, turbulence can't be sustained and laminarization is occurred. Using direct numerical simulation, we measure mean lifetimes of localized turbulence in plane channel flow and investigate their dependence on the number of coherent structures by changing the spanwise length of the domain. Consequently the mean lifetime at a certain Reynolds number increases exponentially as a function of the number of coherent structures. This indicates that each coherent structure contributes to the lifetime independently.
