[aspect-devel] Is the correct Boussinesq approximation now the default in ASPECT?

[Timo Heister]

>> How does one make certain that we are approximating solutions of the correct incompressible Mantle Convection Equations when running the current ASPECT master branch.

As Max said, you need to check that

> subsection Formulation
>   set Formulation          = boussinesq approximation # default: custom

is set. Note that we did not change the default behavior in ASPECT.

The current plan is to release ASPECT 1.5 soon, which allows BA, ALA,
etc. but doesn't use it by default. We will then switch to working on
ASPECT 2.0 where we can introduce breaking changes and decide about
better defaults, not only with respect to formulations.

>> Also John Naliboff suggested that I also ask if the defaults are still no internal heating, adiabatic heating, etc. etc.

Defaults did not change, but if you select the BA formulation and have
incorrect heating settings, we will abort the program. See
Simulator<dim>::check_consistency_of_formulation() or
https://github.com/geodynamics/aspect/blob/2aac1f2342460dbce0f0f94180e79c1774cdf299/source/simulator/helper_functions.cc#L1382

>> The genesis of this particular post is that we are getting startling different results with the same parameter file and presumably, the same code for a problem we're currently working on.

Interesting. That would be worth exploring further.