[mesa-users] On the MLT++

[Mathieu]

Hi everyone,

I would like some more detailed information regarding the MLT++, that I 
could not find neither in the second MESA paper, nor in the documentation.

First of all: Why call it MLT*++*? As far as I understand, it is just a 
trick to help convergence and avoid pressure inversions which in 
principle could be physical (or something like mass loss, or photon 
bubbles could prevent them).

Second, and more important: What happens to the energy flux when MLT++ 
sets in?
MLT++ artificially decreases the superadiabaticity to enforce a 
near-adiabatic stratification of the structure, so what happens in 
convective regions where the superadiabaticity is reduced? Will MESA 
shut down convection there (it seems to me it doesn't)? And what about 
the convective energy flux, which is proportional to the 
superadiabaticity to the 3/2-power? Is it changed by the MLT++, and if 
yes, does the reduced flux imply that a larger amount of energy is 
trapped inside the star?
 From this email exchange 
http://sourceforge.net/p/mesa/mailman/message/32229940/ it seems that 
the energy is nevertheless carried out by the unknown mechanism 
represented by the MLT++, but I am still confused.

Thanks in advance,

Mathieu