Energetics of numerical geodynamo models

Numerical Simulations of Geodynamo and Liquid Metal Convection

Saturation and time dependence of geodynamo models

In this study we address the question under which conditions a saturated velocity field stemming from geodynamo simulations leads to an exponential growth of the magnetic field in a corresponding kinematic calculation. We perform global self-consistent geodynamo simulations and calculate the evolution of a kinematically advanced tracer field. The self-consistent velocity field enters the induct...

Development of Numerical Methods for Geodynamo and Mantle Convection Simulations

2. Development of New Spherical Grid: Yin-Yang Grid Since the finite difference method enables us to make highly optimized programs for massively parallel computers, we exploit the possibility of the finite difference method for simulations in spherical shell geometry with radius r (ri ≤ r ≤ ro), colatitude θ (0 ≤ θ ≤ π), and longitude φ (0 ≤ φ < 2π). Because there is no grid mesh that is ortho...

Energetics of thermal ratchet models

Several stochastic models called thermal ratchet models have been recently proposed to analyze the motor proteins such as myosin and kinesin,etc. We propose a method to study the energetics of those models, and show how the rate of energy consumption and the energy dissipation are evaluated. As a demonstration we consider ”Feynman’s ratchet”, a typical fluctuating heat engine. The motor protein...

Numerical modeling of the geodynamo' of field generation and equilibration Mechanisms

Numerical calculations of fluid dynamos powered by thermal convection in a rotating, electrically conducting spherical shell are analyzed. We find two regimes of nonreversing, strong field dynamos at Ekman number 10 -4 and Rayleigh numbers up to 11 times critical. In the strongly columnar regime, convection occurs only in the fluid exterior to the inner core tangent cylinder, in the form of nar...