title: Heat and momentum transfer for magnetoconvection in a vertical external magnetic field.
abstract: The scaling theory of Grossmann and Lohse [J. Fluid Mech. 407, 27 (2000)JFLSA70022-112010.1017/S0022112099007545] for turbulent heat and momentum transfer is extended to the magnetoconvection case in the presence of a (strong) vertical magnetic field. A comparison with existing laboratory experiments and direct numerical simulations in the quasistatic limit allows us to restrict the parameter space to very low Prandtl and magnetic Prandtl numbers and thus to reduce the number of unknown parameters in the model. Also included is the Chandrasekhar limit, for which the outer magnetic induction field B is large enough such that convective motion is suppressed and heat is transported by diffusion. Our theory identifies four distinct regimes of magnetoconvection that are distinguished by the strength of the outer magnetic field and the level of turbulence in the flow, respectively.
authors.affiliation: Institut für Thermo- und Fluiddynamik, Technische Universität Ilmenau, Postfach 100565, D-98684 Ilmenau, Germany.
authors.forename: Till
authors.initials: T
authors.lastname: Zürner
authors.affiliation: Institut für Thermo- und Fluiddynamik, Technische Universität Ilmenau, Postfach 100565, D-98684 Ilmenau, Germany.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Liu
authors.affiliation: Institut für Thermo- und Fluiddynamik, Technische Universität Ilmenau, Postfach 100565, D-98684 Ilmenau, Germany.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Krasnov
authors.affiliation: Institut für Thermo- und Fluiddynamik, Technische Universität Ilmenau, Postfach 100565, D-98684 Ilmenau, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Schumacher