European Turbulence Conference 2015

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11:00
15 mins

Stability and exact coherent structures of the asymptotic suction boundary layer with temperature gradient
Stefan Zammert, Bruno Eckhardt

Session: Instability and Transition 3
Session starts: Wednesday 26 August, 10:30
Presentation starts: 11:00
Room: Room A

Stefan Zammert (Philipps-Universität Marburg)
Bruno Eckhardt (Philipps-Universität Marburg)

Abstract:
The asymptotic suction boundary layer with a temperature gradient is a good point of entry to study the dynamics of thermal boundary layers by means of dynamical systems theory. The laminar flow without heating is parallel and its properties have been studied before. We add a temperature difference between the bottom plate and the free stream flow, and study the stability in dependence on Reynolds, Rayleigh and Prandtl number. In marked contrast to the usual Rayleigh-B\'enard problem, the onset of convection is subcritical. Tracking secondary bifurcations we identify time-periodic, spanwise, and doubly-localized exact coherent states for this flow.