Other
Scientific paper
Jan 1993
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993phdt........52l&link_type=abstract
PhD Dissertation, Yale Univ. New Haven, CT United States
Other
5
Mixing Length Flow Theory, Stellar Interiors, Stellar Models, Stellar Luminosity, Stellar Convection, Centaurus Constellation, Sun, Three Dimensional Models, Stellar Evolution, Turbulence, Convective Heat Transfer
Scientific paper
One long-standing goal of numerical simulations of turbulent convection has been the removal of the mixing-length theory (MLT) of convective energy transport from stellar structure and evolution calculations; a thorough description is provided of how such a goal may be achieved using a statistical formulation for the energy fluxes and velocities occurring within a convective region. The bases of this technique are approximate relationships between dynamic and thermodynamic properties derived from three-dimensional numerical simulations of compressible convection. These convective flux approximations are applied to the Sun, alpha Centauri A and B, and the cores of a 2 M(solar mass) star and a 5 M(solar mass) star. The results of all stellar models are compared to measured luminosities, radii, and, in the case of the Sun, the depth of the convection zone and the measured p-mode oscillation frequencies. Several conclusions are reached. First, the removal of MLT from a solar model allows for the use of the solar age as a free parameter; this technique yields an age of 4.5 +/- 0.5 Gyrs, a value consistent with the ages of the oldest meteorites. Second, a radius of 0.87 R(solar mass) and an effective temperature of 5200 K are found for alpha Centauri B; observations will test this prediction. Third, in the case of the Sun and alpha Centauri A and B, a single value of the mixing-length parameter may be appropriate for all three stars; this result supports the use of stellar isochrones based upon MLT to determine the ages of star clusters. Fourth, the p-mode oscillation frequencies of a solar model constructed using the convective flux approximations are 1-5 mu Hz greater than the frequencies of an otherwise identical model constructed using MLT; this represents a small improvement in the present conflict between the observed p-mode frequencies and attempts to reproduce the frequencies theoretically. Finally, MLT does, in fact, successfully reproduce many of the gross features of fully compressible, stratified, turbulent convection.
No associations
LandOfFree
The application of numerical simulations of convection to stellar interiors 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 The application of numerical simulations of convection to stellar interiors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The application of numerical simulations of convection to stellar interiors will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1264464