Re: mesa-users] Brunt-vaisala frequency and gradB

[Bill P. <pa...@ki...>]

Hi Josh,

Please try the new release, 2578 and let me know what you find.

gradB is gone and brunt N^2 is calculated differently.
Following Mike Montgomery, we now compute N^2 using the following formula:

	N^2 = (g/r)*( (1/Gamma1)*(dln p/dln r) - (dln \rho/d ln r) )

s% brunt_N2(k) has the value at the outer boundary of cell k.
This is always calculated now, independent of alpha_semiconvection or
thermo_haline_coeff.  and there is no eval_gradB flag either.

The actual calculation is in the routine do_brunt_N2_for_cell in star/private/micro.f
It is using the "raw" profiles of P, Rho, and R without any smoothing, so you
will find some small jitters in the N^2 profile.   Here's an example from a WD, M=0.82 Msun.
(the negative values at the surface are where N^2 < 0)