Yes.The Roe average is a common method in this area. I couldn't understand well what you said about stashing the quantities. Each residual evaluation is proceeded by a Jacobian one if I choose an Inexact Newton method and freeze Jacobian matrix for some Newton iterations. Please make it for me more clear. Thanks a lot,
On Sat, Nov 12, 2011 at 9:29 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote: > On Sat, Nov 12, 2011 at 11:50, behzad baghapour < > behzad.baghapour at gmail.com> wrote: > >> The nonlinear residual and Jacobian matrix are evaluated with a >> face-based method. Two integrals are involved (the effect of element >> internal connections and face flux connections). All of my calculations of >> flow states are solved and stored in arrays of objects called elements. > > > Are you talking about intermediate quantities like Roe averages on face > quadrature points? The state X at which the residual is evaluated is > different each time, so you would be using old values if you stashed them. > The residual might be evaluated multiple times before a Jacobian is > requested. Normally the residual is much less expensive than the Jacobian, > so it's not worth stashing the intermediate quantities. See also this FAQ: > > > http://www.mcs.anl.gov/petsc/petsc-as/documentation/faq.html#functionjacobian > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20111112/7343247b/attachment.htm>
