On Fri, Jul 5, 2024 at 3:29 AM Miguel Angel Salazar de Troya < miguel.sala...@corintis.com> wrote:
> Hello, I have the Navier-Stokes equation coupled with a > convection-diffusion equation for the temperature. It is a two-way coupling > because the viscosity depends on the temperature. One way to solve this is > with some kind of fixed point iteration > ZjQcmQRYFpfptBannerStart > This Message Is From an External Sender > This message came from outside your organization. > > ZjQcmQRYFpfptBannerEnd > Hello, > > I have the Navier-Stokes equation coupled with a convection-diffusion > equation for the temperature. It is a two-way coupling because the > viscosity depends on the temperature. One way to solve this is with some > kind of fixed point iteration scheme, where I solve each equation > separately in a loop until I see convergence. I am aware this is not > possible directly at the SNES level. Is there something that one can do > using PCFIELDSPLIT? I would like to assemble my fully coupled system and > play with the solver options to get some kind of fixed-point iteration > scheme. I would like to avoid having to build two separate SNES solvers, > one per equation. Any reference on techniques to solve this type of coupled > system is welcome. > Hi Miguel, I have a branch https://urldefense.us/v3/__https://gitlab.com/petsc/petsc/-/tree/knepley/feature-snes-fieldsplit?ref_type=heads__;!!G_uCfscf7eWS!cqtcQdi0PKTs4S7KpYIdusFz-Sr1TBcqFksEpoLFWkYiP_DAZlbbQdGCNTEQxScvJW1Tm0fsMaqh1YxTAA-_$ that will allow you to do exactly what you want to do. However, there are caveats. In order to have SNES do this, it needs a way to selectively reassemble subproblems. I assume you are using Firedrake, so this will not work. I would definitely be willing to work with those guys to get this going, introducing callbacks, just as we did on the FieldSplit case. Thanks, Matt > Best, > Miguel > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!cqtcQdi0PKTs4S7KpYIdusFz-Sr1TBcqFksEpoLFWkYiP_DAZlbbQdGCNTEQxScvJW1Tm0fsMaqh1RE4uZs7$ <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!cqtcQdi0PKTs4S7KpYIdusFz-Sr1TBcqFksEpoLFWkYiP_DAZlbbQdGCNTEQxScvJW1Tm0fsMaqh1beuGI7M$ >
