[mesa-users] Meaning of f_2 and D_2 parameters (RICHARD H D TOWNSEND)

Umberto Battino umberto.battino at unibas.ch
Mon Apr 4 11:03:10 EDT 2016


Hello Richard,

I've recently submitted a paper where I test the f_2 and D_2 parameters in low-mass AGB evolution. In this paper I want to describe the Convective-Boundary Mixing (CBM) processes in AGB accounting to Internal Gravity Waves (IGW) effect in addition to the classic convective overshooting (see Herwig 2000). Therefore, I need a parametrization able to account to 2 distinct processes.

See the attached plot for a schematic description of how those parameters act:

The red line is the standard overshooting mixing coe?fficient pro?file following the single-exponential decay. This profi?le is dominated by a single 'f1' parameter which determines the slope of the mixing profi?le: the lower the 'f1' value, the steeper the pro?file is. In order to take into account IGW, in this work I apply a second, slower, decreasing pro?file (green line) that becomes more relevant than the ?first one as soon as the mixing coe?fficient is equal or lower that a 'D2' value, the slope of which is determined by the 'f2' parameter.

Hoping this helps!

Cheers,

 Umberto




-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20160404/ca44ac38/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: CBM_schematic.png
Type: image/png
Size: 211680 bytes
Desc: CBM_schematic.png
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20160404/ca44ac38/attachment.png>


More information about the Mesa-users mailing list