Hello! So far I'd been using an RK3 integrator that I had written myself. To rectify the problem I faced (mentioned in the mail earlier), I thought of, was using the built-in explicit RK4 integrator TimeStepping::ExplicitRungeKutta <https://dealii.org/developer/doxygen/deal.II/classTimeStepping_1_1ExplicitRungeKutta.html> . Now, I have a function called "assemble_rhs" that uses MeshWorker to evaluate the rhs of the explicit time dependent equation. Its signature is: Step12<dim>::assemble_rhs (RHSIntegrator<dim>& rhs_integrator) (I'm modifying part of the step-12 tutorial program). But the evolve_one_step function is of format: TimeStepping::ExplicitRungeKutta <https://dealii.org/developer/doxygen/deal.II/classTimeStepping_1_1ExplicitRungeKutta.html>< VectorType >::evolve_one_time_step ( const std::function< VectorType(const double, const VectorType &)> & f, double t, double delta_t, VectorType & y ) To this, I tried to pass assemble_rhs as the first arg and ofcourse it failed to compile. I've not been able to figure out how do I use my rhs function to get to evaluate the next time-step. I'm probably making quite a fundamental mistake, can you please guide me?
Thank You, Apurva On Tue, 12 Mar 2019 at 17:04, Apurva Tiwari <[email protected]> wrote: > Hello! > I'm trying to get appropriate convergence rates for a 2D scalar advection > problem. The strategy is quite standard. I start with a coarse grid, > successively refine it globally and generate the convergence table as done > in step-7. As can be seen in the attached convergence tables, the values > are far off. What all could have gone wrong and where do I start debugging > my code from? What are the things to check? > I'm using Q1, Q2 and Q3 elements with RK3 time-stepping. The initial > condition is an off-centered Gaussian which is subjected to a rotational > velocity field. > > PFA: "error-global-order1.pdf " > "error-global-order2.pdf " > "error-global-order3.pdf " > > Thank You, > Apurva Tiwari > -- Apurva Tiwari -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
