TY  - BOOK
A1  - Schumacher, Jörg
A1  - Kliem, Bernhard
A1  - Seehafer, Norbert
T1  - Three-dimensional spontaneous magnetic reconnection in neutral current sheets
T3  - Preprint series / Astrophysikalisches Institut Potsdam
Y1  - 1999
VL  - 99,42
PB  - AIP
CY  - Potsdam
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  - 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  - Seehafer, Norbert
T1  - Filaments and the solar dynamo
Y1  - 1998
SN  - 1-88673-370-8
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  - Zienicke, Egbert
A1  - Seehafer, Norbert
A1  - Feudel, Fred
T1  - Bifurcations in two-dimensional Rayleigh-Bénard convection
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Scheel, S.
A1  - Seehafer, Norbert
T1  - Bifurcation to oscillations in three-dimensional Rayleigh-Bénard convection
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Braun, Robert
A1  - Feudel, Fred
A1  - Seehafer, Norbert
T1  - Bifurcations and chaos in an array of forced vortices
Y1  - 1997
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  - Seehafer, Norbert
A1  - Schumacher, Jörg
T1  - Resistivity profile and instability of the plane sheet pinch
Y1  - 1998
ER  - 
TY  - BOOK
A1  - Seehafer, Norbert
A1  - Schumacher, Jörg
T1  - Resistivity profile and instability of the plane sheet pinch
T3  - Preprint NLD
Y1  - 1998
SN  - 1432-2935
VL  - 44
PB  - Univ. Potsdam
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Feudel, Fred
A1  - Seehafer, Norbert
A1  - Schmidtmann, Olaf
T1  - Bifurcation phenomena of the magnetofluid equations
N2  - We report on bifurcation studies for the incompressible magnetohydrodynamic equations in three space dimensions with periodic boundary conditions and a temporally constant external forcing. Fourier representations of velocity, pressure and magnetic field have been used to transform the original partial differential equations into systems of ordinary differential equations (ODE), to which then special numerical methods for the qualitative analysis of systems of ODE have been applied, supplemented by the simulative calculation of solutions for selected initial conditions. In a part of the calculations, in order to reduce the number of modes to be retained, the concept of approximate inertial manifolds has been applied. For varying (increasing from zero) strength of the imposed forcing, or varying Reynolds number, respectively, time-asymptotic states, notably stable stationary solutions, have been traced. A primary non- magnetic steady state loses, in a Hopf bifurcation, stability to a periodic state with a non-vanishing magnetic field, showing the appearance of a generic dynamo effect. From now on the magnetic field is present for all values of the forcing. The Hopf bifurcation is followed by further, symmetry-breaking, bifurcations, leading finally to chaos. We pay particular attention to kinetic and magnetic helicities. The dynamo effect is observed only if the forcing is chosen such that a mean kinetic helicity is generated; otherwise the magnetic field diffuses away, and the time-asymptotic states are non-magnetic, in accordance with traditional kinematic dynamo theory.
Y1  - 1996
UR  - http://www.mathematicsweb.org/mathematicsweb/show/Index.htt?Issn=03784754
ER  - 
TY  - JOUR
A1  - Schmidtmann, Olaf
A1  - Feudel, Fred
A1  - Seehafer, Norbert
T1  - Nonlinear Galerkin methods for the 3D magnetohydrodynamic equations
Y1  - 1997
ER  - 
TY  - BOOK
A1  - Zienicke, Egbert
A1  - Seehafer, Norbert
A1  - Feudel, Fred
T1  - Bifurcations in two-dimensional Rayleigh-Bénard convection
T3  - Preprint NLD
Y1  - 1997
SN  - 1432-2935
VL  - 42
PB  - Univ. Potsdam
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Scheel, S.
A1  - Seehafer, Norbert
T1  - Bifurcation to Oscillations in three-dimensional Rayleigh-Bénard convection
T3  - Preprint NLD
Y1  - 1997
SN  - 1432-2935
VL  - 39
PB  - Univ. Potsdam
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Schmidtmann, Olaf
A1  - Feudel, Fred
A1  - Seehafer, Norbert
T1  - Nonlinear Galerkin methods for the 3D magnetohydrodynamic equations
T3  - Preprint NLD
Y1  - 1997
SN  - 1432-2935
VL  - 35
PB  - Univ. Potsdam
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Seehafer, Norbert
A1  - Zienicke, Egbert
A1  - Feudel, Fred
T1  - Absence of magnetohydrodynamic activity in the voltage-driven sheet
T3  - Preprint NLD
Y1  - 1996
VL  - 32
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Braun, Robert
A1  - Feudel, Fred
A1  - Seehafer, Norbert
T1  - Bifurcations and chaos in an array of forced vortices
T3  - Preprint NLD
Y1  - 1997
SN  - 1432-2935
VL  - 37
PB  - Univ. Potsdam
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Seehafer, Norbert
A1  - Schumacher, Jörg
T1  - Squire's theorem for the magnetohydrodynamic sheet pinch
Y1  - 1997
ER  - 
TY  - BOOK
A1  - Seehafer, Norbert
A1  - Schumacher, Jörg
T1  - Squire's theorem for the magnetohydrodynamic sheet pinch
T3  - Preprint NLD
Y1  - 1997
SN  - 1432-2935
VL  - 40
PB  - Univ. Potsdam
CY  - Potsdam
ER  -