PreprintSpherical Single-Roll Dynamos at Large Magnetic Reynolds NumbersDavid Ivers and Henrik LatterAbstractThe asymptotic theory of Gilbert and Ponty (2000) for axisymmetric spherical roll flow dynamos at large magnetic Reynolds \(R_m\) numbers is compared to the numerical eigen-solutions for two flows. The flows are the \(s^0_1t^0_1\) of Dudley and James(1989) and an \(s^0_1t^0_1t^0_3\) modification of it. The numerical method uses the hybrid vector spherical harmonic technique of Ivers and Phillips (2003) with fourth-order finite-differences. Excellent agreement is in the asymptotic regime \(R_m > 10,000\) for both the growth rate and the angular frequency. The asymptotic theory is extended to the next order. Keywords: magnetohydrodynamics, kinematic dynamos, asymptotic theory.
This paper is available as a pdf (2116kB) file.
|