Statistics – Computation
Scientific paper
May 2000
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000ohbp.conf...67f&link_type=abstract
"In: The outer heliosphere: beyond the planets. Based on the spring school "Die äußere Heliosphäre - Jenseits der Planeten, in B
Statistics
Computation
1
Interplanetary Space, Dynamics, Coronal Magnetic Field
Scientific paper
In many papers in the literature it is shown that wind-driving stars with a peculiar motion relative to the ambient interstellar medium within dynamical time periods form a dynamically adapted astropause as separatrix between the stellar wind plasma and the surrounding interstellar plasma. As we shall show in this chapter stars with an adapted astropause are subject to thrust forces finally acting on the wing-generating central body and thus influencing the stellar motion. Thereby the actual magnitude of the resulting thrust force depends on the actual counterflow configuration of stellar and interstellar winds determined by the particular kinematic situation, i.e. the instantaneous Mach number of the motion relative to the ambient medium. We shall study the sensitivity of this configuration to whether the interstellar flow is sub- or supersonic. The resulting net force is shown to vary in a non-monotonic way with the actual peculiar velocity. For subsonic motions this force generally has an accelerating nature, i.e. operating like a rocket thrust motor, whereas for supersonic motions at supercritical Mach numbers μS≥μS,c, to the contrary, it is of a decelerating nature. For an adequate description of a time-dependent circumstellar flow configuration, we shall use an analytic, hydrodynamic modeling of the counterflow configuration representing the case of a stellar wind system in subsonic or supersonic motion with respect to the local interstellar medium. For the purpose of analytical treatability we assume irrotational and incompressible flows downstream of the inner and outer shocks and give quantitative numbers for forces acting on the central star. We also describe long-period evolutions of star motions and give typical acceleration time periods for different types of wind-driving stars. As we shall emphasize here the dynamical influence of these thrust forces onto the central stellar body requires an understanding of how the presence of the counterflowing interstellar plasma is communicated upstream in the supersonic stellar wind up to the origin of this wind, the stellar corona. The answer we shall give is based on the multifluid character of the relevant counterflow situation invalidating the conventional mono-Mach-number concept of hydrodynamical flows. In fact stellar winds can only be described by a poly-Mach-number concept, with stellar-wind protons being supersonic, with pick-up ions being marginally sonic, and with electrons and anomalous cosmic ray particles being strongly subsonic. We shall present solutions for multifluid counterflow configurations based on computational simulations in which a consistent picture of the interaction of all these different species is given. Our final conclusion is that already the solar wind when passing over the Earth's orbit tells us about the interstellar medium beyond the heliopause.
No associations
LandOfFree
Formation of the heliospheric boundaries and the induced dynamics of the solar system: a multifluid view does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Formation of the heliospheric boundaries and the induced dynamics of the solar system: a multifluid view, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Formation of the heliospheric boundaries and the induced dynamics of the solar system: a multifluid view will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1199733