[petsc-users] TS_SSP implementation for co-dependent variables

[Jed Brown]

Manuel Valera via petsc-users <petsc-users at mcs.anl.gov> writes:

> Hello,
>
> I have a set of equations which are co-dependent when integrating in time,
> this means the velocities u,v,w need a component from the Temperature and
> Salinity integration at the same intermediate step. Same for Temperature
> and Salinity, which need the current velocities (at the intermediate time
> stages) to be computed accurately.

There's nothing special about having different fields.  Just evaluate
the RHS function of the coupled system.  There are examples (e.g.,
ts/examples/tutorials/ex9.c) of doing this for systems like shallow
water (momentum coupled with thickness).

> My question is, how to feed the information of the updated temperature
> inside the velocity, and vice-versa? this would be equivalent, I think, to
> obtaining the intermediate stages of the time integration so they can be
> the input for the next intermediate stage.
>
> Thanks,