Jed, For the proposal, Heeho wants to demonstrate that a (well?) tuned black box preconditioner does not perform well (e.g. ILU[k], ILU[dt]). Ultimately, he plans to build on work by Qang Bui (currently a post-doc at LLNL), which is aligned with what you propose below, e.g.
Bui, Quan & Wang, Lu & Osei-Kuffuor, Daniel. (2018). Algebraic Multigrid Preconditioners for Two-phase Flow in Porous Media with Phase Transitions. Advances in Water Resources. 114. 10.1016/j.advwatres.2018.01.027. Bui, Quan & C. Elman, Howard & Moulton, J. (2016). Algebraic Multigrid Preconditioners for Multiphase Flow in Porous Media. SIAM Journal on Scientific Computing. 39. 10.1137/16M1082652. So, at this point, Heeho is looking for the best out-of-the-box preconditioners to demonstrate their poor performance. Or perhaps he should just employ PETSc's ILU[k] and move on.... Glenn > -----Original Message----- > From: Jed Brown <[email protected]> > Sent: Tuesday, March 5, 2019 9:06 PM > To: Park, Heeho <[email protected]>; [email protected] > Cc: Park, Heeho Daniel <[email protected]>; Hammond, Glenn E > <[email protected]> > Subject: [EXTERNAL] Re: [petsc-dev] external preconditioner availablilty for > PETSc > > From a research perspective, it doesn't make sense to view these > preconditioners as black boxes. Your problem will likely have an elliptic > component (which you might approach using a multilevel method such as > PCGAMG, PCML, PCHYPRE, or PCBDDC, all of which can accept some > problem-specific input information as well as tunable parameters) combined > (perhaps using PCFIELDSPLIT) with a transport solver (perhaps one-level > domain decomposition). The details of the splits will take some thought and > you'll want to compare to monolithic (unsplit) 1-level domain decomposition > methods with suitably chosen subdomains and/or geometric multigrid. One > way to start would be to do a literature search and try to reproduce the > results from some methods in the literature. After that, you'll have a > baseline for comparison and probably get some ideas about composition. > > "Park, Heeho via petsc-dev" <[email protected]> writes: > > > Hi PETSc developers, > > > > I’m writing my proposal for my dissertation research at UIUC that will study > on effectiveness of preconditioners for anisothermal, multiphase porous > media flow calculations in parallel using PFLOTRAN. I know the link below > lists > preconditioners but from your experience, which preconditioning packages > provide reliable and efficient PILUT, AMG, SA-AMG preconditioners for > PETSc and do you have other preconditioner recommendations? > > I used hypre PILUT, but the performance and the linear iteration count to > solve a matrix is worse than ILU(0) which is not what I expected. > > > > https://www.mcs.anl.gov/petsc/documentation/linearsolvertable.html > > > > Heeho Daniel Park > > > > ! ------------------------------------ ! > > Sandia National Laboratories > > Org: 08844, R&D > > Work: 505-844-1319 > > ! ------------------------------------ !
