[petsc-users] Implementing TS routine

[Manuel Valera]

Hi PETSc,

I am trying to implement the Time stepping routines in my model, i have a
working runge-kutta time scheme that goes to the following steps:


   - Interpolate u,v,w to the time advancing variable position.
   - Calculate nonlinear coefficients and advect velocities with a
   forward-backward shock capturing scheme.
   - Calculate the variable laplacian
   - Sum terms to create RHS (nonlinear advected velocities + laplacian)
   - Finally, the runge kutta integration is done in a typical way that
   looks like:

                   newtemp(t+1) = prevtemp(t) + dt*RHS


So my questions are:

   - I think my problem is nonlinear, but is being made linearized by the
   advecting scheme, is this correct? this is to know if i should use the
   linear or nonlinear routines for TS.
   - How do i know what are the appropriate routines i should be using
   here? so far i think i should use the following:

call TSCreate(PETSC_COMM_WORLD,ts,ierr)
call TSSetProblemType(ts,TS_LINEAR,ierr)
call TSSetTimeStep(ts,dt,ierr)

call TSSetFromOptions(ts,ierr)

call TSSetRHSFunction(ts,NULL,TSComputeRHSFunctionLinear,NULL,ierr)
call TSSolve(ts,loctemperature,ierr)

Should i use call TSSetRHSJacobian for the temperature jacobian in this
case?

I am using
https://www.mcs.anl.gov/petsc/petsc-current/src/ts/examples/tutorials/ex4.c.html
as
a  general guide, is there a more appropriate example?

The dt value and total timesteps are controlled by the model,

Thanks for your help,
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