Mathematics – Logic
Scientific paper
May 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010aas...21622102b&link_type=abstract
American Astronomical Society, AAS Meeting #216, #221.02; Bulletin of the American Astronomical Society, Vol. 41, p.893
Mathematics
Logic
Scientific paper
Magnetohydrodynamics (MHD) is sometimes conceived of as hydrodynamics with the Lorentz force added as an extra term. This way of thinking oversimplifies matters however, because MHD not only includes a new force, but also includes the constraint that magnetic flux is frozen into the fluid frame. The combination of the new force and the new constraint results in processes that are unimaginable in the context of hydrodynamics. Numerous astrophysical situations exist where MHD dominates and causes behavior bearing no relationship to classical hydrodynamics. For example, the solar corona contains large numbers of distinct plasma-filled arched flux tubes that emerge, twist up, and sometimes violently explode. Astrophysical jets are another example: these plasma jets are extremely collimated MHD-driven flows that propagate at high velocities away from various types of central objects.
Because MHD is scale-independent and because solar coronal loops and astrophysical jets to lowest order are independent of gravity, it is possible to recreate the essential physics of these plasma phenomena in controlled laboratory experiments. The essential requirement is to create a plasma where (i) MHD forces dominate, (ii) magnetic flux is frozen into the frame of the plasma, and (iii) boundary conditions are topologically analogous to the relevant astrophysical boundary conditions. Experiments of this sort underway at Caltech for several years will be discussed. The understanding obtained from these experiments shows that solar coronal loops and astrophysical jets have much in common.
Supported by USDOE, NSF, and AFOSR
No associations
LandOfFree
Astrophysics without Gravity: When the Lorentz Force (MHD) Dominates 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 Astrophysics without Gravity: When the Lorentz Force (MHD) Dominates, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Astrophysics without Gravity: When the Lorentz Force (MHD) Dominates will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1889655