Precession-driven dynamos in ellipsoidal planets

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So far numerical simulations have mostly assumed that the flow generating the dynamo-process is driven by buoyancy forces. But also precession can drive the dynamo, as first suggested by Bullard in 1949. We are going to investigate the properties of precession-driven planetary dynamos by the use of a finite volume code. In the planets it is much more effective to drive a precessional flow by the pressure differences induced by the topography of the precessing body than by viscous coupling to the walls. Therefore we will modify the existing program, which is a finite volume code for spherical shells, so that the magneto-hydrodynamic equations in ellipsoidal shells are solved. We are going to investigate the characteristic features of the magnetic fields of precession driven dynamos and compare them to the planetary magnetic fields.