TY  - JOUR
A1  - Feudel, Fred
A1  - Tuckerman, Laurette S.
A1  - Zaks, Michael
A1  - Hollerbach, Rainer
T1  - Hysteresis of dynamos in rotating spherical shell convection
JF  - Physical review fluids / American Physical Society
N2  - Bifurcations of dynamos in rotating and buoyancy-driven spherical Rayleigh-Benard convection in an electrically conducting fluid are investigated numerically. Both nonmagnetic and magnetic solution branches comprised of rotating waves are traced by path-following techniques, and their bifurcations and interconnections for different Ekman numbers are determined. In particular, the question of whether the dynamo branches bifurcate super- or sub-critically and whether a direct link to the primary pure convective states exists is answered.
Y1  - 2017
U6  - https://doi.org/10.1103/PhysRevFluids.2.053902
SN  - 2469-990X
VL  - 2
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Feudel, Fred
A1  - Seehafer, Norbert
A1  - Tuckerman, Laurette S.
T1  - Multistability in rotating spherical shell convection
Y1  - 2013
UR  - http://link.aps.org/doi/10.1103/PhysRevE.87.023021 (9.9.2013)
SN  - 1539-3755
ER  - 
TY  - JOUR
A1  - Feudel, Fred
A1  - Seehafer, Norbert
A1  - Tuckerman, Laurette S.
A1  - Gellert, Marcus
T1  - Multistability in rotating spherical shell convection
JF  - Physical review : E, Statistical, nonlinear and soft matter physics
N2  - The multiplicity of stable convection patterns in a rotating spherical fluid shell heated from the inner boundary and driven by a central gravity field is presented. These solution branches that arise as rotating waves (RWs) are traced for varying Rayleigh number while their symmetry, stability, and bifurcations are studied. At increased Rayleigh numbers all the RWs undergo transitions to modulated rotating waves (MRWs) which are classified by their spatiotemporal symmetry. The generation of a third frequency for some of the MRWs is accompanied by a further loss of symmetry. Eventually a variety of MRWs, three-frequency solutions, and chaotic saddles and attractors control the dynamics for higher Rayleigh numbers.
Y1  - 2013
U6  - https://doi.org/10.1103/PhysRevE.87.023021
SN  - 1539-3755
VL  - 87
IS  - 2
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Feudel, Fred
A1  - Bergemann, Kay
A1  - Tuckerman, Laurette S.
A1  - Egbers, C.
A1  - Futterer, B.
A1  - Gellert, Marcus
A1  - Hollerbach, Rainer
T1  - Convection patterns in a spherical fluid shell
JF  - Physical review : E, Statistical, nonlinear and soft matter physics
N2  - Symmetry-breaking bifurcations have been studied for convection in a nonrotating spherical shell whose outer radius is twice the inner radius, under the influence of an externally applied central force field with a radial dependence proportional to 1/r(5). This work is motivated by the GeoFlow experiment, which is performed under microgravity condition at the International Space Station where this particular central force can be generated. In order to predict the observable patterns, simulations together with path-following techniques and stability computations have been applied. Branches of axisymmetric, octahedral, and seven-cell solutions have been traced. The bifurcations producing them have been identified and their stability ranges determined. At higher Rayleigh numbers, time-periodic states with a complex spatiotemporal symmetry are found, which we call breathing patterns.
Y1  - 2011
U6  - https://doi.org/10.1103/PhysRevE.83.046304
SN  - 1539-3755
VL  - 83
IS  - 4
PB  - American Physical Society
CY  - College Park
ER  -