Imperfect supercritical bifurcation in a three-dimensional turbulent wake.

Kinematics and Dynamics of Sphere Wake Transition

The wake of a sphere undergoes a number of symmetry-breaking transitions as it changes from laminar to turbulent. This paper concentrates on the "rst two transitions. At Re"212 a regular transition occurs, when the wake develops a spectacular two-tailed structure consisting of two trailing streamwise vortices. During the second transition at Re"272 the #ow undergoes a Hopf bifurcation. In this ...

Numerical Predictions of Turbulent Mixed Convection Heat Transfer to Supercritical Fluids Using Various Low Reynolds Number k-e Turbulence Models

There are a number of systems in which supercritical cryogenic fluids are used as coolants or propellant fluids. In some modern military aircraft, the fuel is pressurized above its critical point and used as a coolant to remove heat from the aircraft engine. Accurate prediction of heat transfer coefficients to turbulent flows of supercritical fluids is essential in design of such systems. One o...

Reflectional symmetry breaking of the separated flow over three-dimensional bluff bodies.

Experimental observation of a permanent reflectional symmetry breaking (RSB) is reported for a laminar three-dimensional wake. Based on flow visualizations, a first bifurcation from the trivial steady symmetric state to a steady RSB state is characterized at Re=340. The RSB state becomes unsteady after a second bifurcation at Re=410. It is found that this RSB regime is persistent at large Reyno...

A coupled Landau model describing the Strouhal–Reynolds number profile of a three-dimensional circular cylinder wake

A known bifurcation scenario describing the development and interaction of Mode A and Mode B vortex shedding modes of a circular cylinder wake is extended to predict the Strouhal–Reynolds number profile over the three-dimensional transitions. The mode amplitudes are described by coupled Landau equations and, with frequency information being included by the addition of complex coefficients, the ...

outflow Boundary Codition Issues in Direct Numerical Simulation of Three- Dimensional Plane Wake Flow