On Thu, 4 Apr 2013, Manav Bhatia wrote: > I am attempting to use the TwostepTimeSolver in place of the EulerSolver > for time marching in my code. > > This, however, is leading to unexpected behavior: the nonlinear > residuals drop down to 10^-8 in 3 iterations even though the time step has > changed from 0.05 to 0.051 (should take about 100 iterations).
By "iterations" do you mean Newton iterations? That's the context where "nonlinear residuals" really make sense, but there's no way you should be running a solve that normally takes 100 inexact-Newton steps. > I am in the process of looking into the code, but wanted to run this by > the developers to see if there is something I may be missing to setup the > solver. Maybe something you're missing in the reporting? For each time step of deltat you're now really doing one deltat step and two deltat/2 steps; depending on how your problems nonlinearities behave it's quite possible that the deltat/2 steps are much easier to solve. --- Roy ------------------------------------------------------------------------------ Minimize network downtime and maximize team effectiveness. Reduce network management and security costs.Learn how to hire the most talented Cisco Certified professionals. Visit the Employer Resources Portal http://www.cisco.com/web/learning/employer_resources/index.html _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
