Numerical simulation of the viscous interaction of the solar wind with the magnetic polar regions of Venus

¹ Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo Postal 877, Ensenada 22800, B.C., México e-mail: [maurey;ediaz]@astrosen.unam.mx
² Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria, C.P. 04510, D.F., México e-mail: perezdet@geofisica.unam.mx

Received: 17 December 2007
Accepted: 5 June 2008

Abstract

Aims. We aim to study the viscous interaction of the solar wind with the ionosphere of Venus in the magnetic polar regions by means of hydrodynamical computer simulations.

Methods. We use a finite difference code developed for the solution of the Navier-Stokes, continuity and energy equations.

Results. We have calculated the flow properties, the shape and location of the boundary layer and the shock formed as a consequence of the viscous interaction over the magnetic poles of the planet and advected downstream. By comparing our results to the flow properties measured by the Venera 10 and Mariner 5 spacecraft in the Venus ionosheath, we determine that a Reynolds number for the flow near the value is necessary to reproduce the position of the intermediate transition as well as the shock front. Also, on the basis of our results we predict the existence of a stagnation region for the solar wind flow extending considerably upstream from the viscous interaction region.