On Wed, 4 Dec 2013, Manav Bhatia wrote: > My application is compressible Euler flow, so shock will appear in > the computational domain. Is the L2 norm of density variable, compared with > a reference solution (obtained on a very fine mesh), better or worse than > an H1-seminorm on density? Should some other type of norm be considered? > How about Kelly's error estimator?
Trying to use an H1 norm (or anything derived from it, like Kelly) for adaptive refinement on a shock problem can be a total *disaster*. Basically your real H1 error is infinity, so any finite H1 error estimates are likely to *increase* as you refine into the shock, and this can lead to unstable refinement patterns where you just keep refining in the spots you've already refined. I've got an example slide or two somewhere I could hunt down and upload if you like. What worked decently for me was patch recovery in L2... this was just part of an adjoint-weighted norm in my case, but I suspect it would work fine for global error norm based refinement as well. Ben Kirk's done a bunch of such studies; hopefully he'll chime in too. --- Roy ------------------------------------------------------------------------------ Sponsored by Intel(R) XDK Develop, test and display web and hybrid apps with a single code base. Download it for free now! http://pubads.g.doubleclick.net/gampad/clk?id=111408631&iu=/4140/ostg.clktrk _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
