TY  - BOOK
A1  - Braun, Robert
A1  - Feudel, Fred
A1  - Guzdar, P.
T1  - The route to chaos for a two-dimensional externally driven flow : [to appear in Physical Review E]
T3  - Preprint NLD
Y1  - 1998
SN  - 1432-2935
VL  - 46
PB  - Univ. Potsdam
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Braun, Robert
A1  - Feudel, Fred
A1  - Guzdar, P.
T1  - The route to chaos for a two-dimensional externally driven flow
Y1  - 1998
ER  - 
TY  - INPR
A1  - Braun, Robert
A1  - Feudel, Fred
A1  - Guzdar, Parvez
T1  - The route to chaos for a two-dimensional externally driven flow
N2  - We have numerically studied the bifurcations and transition to chaos in a two-dimensional fluid for varying values of the Reynolds number. These investigations have been motivated by experiments in fluids, where an array of vortices was driven by an electromotive force. In these experiments, successive changes leading to a complex motion of the vortices, due to increased forcing, have been explored [Tabeling, Perrin, and Fauve, J. Fluid Mech. 213, 511 (1990)]. We model this experiment by means of two-dimensional Navier-Stokes equations with a special external forcing, driving a linear chain of eight counter-rotating vortices, imposing stress-free boundary conditions in the vertical direction and periodic boundary conditions in the horizontal direction. As the strength of the forcing or the Reynolds number is raised, the original stationary vortex array becomes unstable and a complex sequence of bifurcations is observed. Several steady states and periodic branches and a period doubling cascade appear on the route to chaos. For increasing values of the Reynolds number, shear flow develops, for which the spatial scale is large compared to the scale of the forcing. Furthermore, we have investigated the influence of the aspect ratio of the container as well as the effect of no-slip boundary conditions at the top and bottom, on the bifurcation scenario.
T3  - NLD Preprints - 46 
Y1  - 1998
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14717
ER  - 
TY  - INPR
A1  - Rüdiger, Sten
A1  - Feudel, Fred
A1  - Seehafer, Norbert
T1  - Dynamo bifurcations in an array of driven convection-like rolls
N2  - The bifurcations in a three-dimensional incompressible, electrically conducting fluid with an external forcing of the Roberts type have been studied numerically. The corresponding flow can serve as a model for the convection in the outer core of the Earth and is realized in an ongoing laboratory experiment aimed at demonstrating a dynamo effect. The symmetry group of the problem has been determined and special attention has been paid to symmetry breaking by the bifurcations. The nonmagnetic, steady Roberts flow loses stability to a steady magnetic state, which in turn is subject to secondary bifurcations. The secondary solution branches have been traced until they end up in chaotic states.
T3  - NLD Preprints - 43 
Y1  - 1998
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14678
ER  - 
TY  - JOUR
A1  - Rüdiger, Sten
A1  - Feudel, Fred
A1  - Seehafer, Norbert
T1  - Dynamo bifurcations in an array of driven convectionlike rolls
Y1  - 1998
ER  - 
TY  - BOOK
A1  - Rüdiger, Sten
A1  - Feudel, Fred
A1  - Seehafer, Norbert
T1  - Dynamo bifurcations in an array of driven convectionlike rolls
T3  - Preprint NLD
Y1  - 1998
SN  - 1432-2935
VL  - 43
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Schmidtmann, Olaf
A1  - Feudel, Fred
A1  - Seehafer, Norbert
T1  - Nonlinear Galerkin methods based on the concept of determining modes for the magnetohydrodynamic equations
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Seehafer, Norbert
A1  - Feudel, Fred
A1  - Galanti, B.
T1  - Bifurcations in a magnetofluid with helical forcing
Y1  - 1998
SN  - 1-563-47284-8
ER  - 
TY  - JOUR
A1  - Witt, Annette
A1  - Feudel, Fred
A1  - Gebogi, C.
A1  - Kurths, Jürgen
A1  - Braun, Robert
T1  - Tracer dynamics in a flow of driven vortices
JF  - Preprint NLD
Y1  - 1998
SN  - 1432-2935
VL  - 51
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Zienicke, Egbert
A1  - Seehafer, Norbert
A1  - Feudel, Fred
T1  - Bifurcations in two-dimensional Rayleigh-Bénard convection
Y1  - 1998
ER  -