MPI p4est parabolic 2D nonconforming AMR with loadbalancing

examples/p4est_2d_dgsem/elixir_advection_diffusion_amr_inverted_index.jl

@@ -0,0 +1,94 @@
+using OrdinaryDiffEqLowStorageRK
+using Trixi
+
+###############################################################################
+# semidiscretization of the linear advection equation
+
+advection_velocity = (3.0, 3.0)
+diffusivity() = 5.0e-2
+equations = LinearScalarAdvectionEquation2D(advection_velocity)
+equations_parabolic = LaplaceDiffusion2D(diffusivity(), equations)
+
+function initial_condition_gauss_static(x, t, equations)
+    # center of the Gaussian (choose safely inside your domain)
+    x0 = -0.5
+    y0 = 1.5
+
+    # width (smaller = more localized)
+    sigma = 0.175
+
+    # Gaussian
+    r2 = (x[1] - x0)^2 + (x[2] - y0)^2
+    u = 2 * exp(-r2 / (2 * sigma^2))
+
+    return SVector(u)
+end
+
+initial_condition = initial_condition_gauss_static
+
+boundary_condition = BoundaryConditionDirichlet((x, t, equations) -> SVector(0.0))
+boundary_conditions = (Bottom = boundary_condition,
+                       Right = boundary_condition,
+                       Top = boundary_condition,
+                       Left = boundary_condition)
+boundary_conditions_parabolic = boundary_conditions
+
+solver = DGSEM(polydeg = 3, surface_flux = flux_lax_friedrichs)
+
+# Unstructured mesh with inverted indexing of the nodes
+# Specifically tests that the node indexing in the mpi parabolic solver is consistent 
+mesh_file = Trixi.download("https://gist.githubusercontent.com/andrewwinters5000/3e7dac35eeadc24739ea29619f78b8d2/raw/ecc29e82be69c656217dc878821917850c51e41d/mesh_wobbly_channel.inp",
+                           joinpath(@__DIR__, "mesh_wobbly_channel.inp"))
+
+mesh = P4estMesh{2}(mesh_file, polydeg = 3,
+                    initial_refinement_level = 1)
+
+semi = SemidiscretizationHyperbolicParabolic(mesh,
+                                             (equations, equations_parabolic),
+                                             initial_condition, solver;
+                                             solver_parabolic = ParabolicFormulationBassiRebay1(),
+                                             boundary_conditions = (boundary_conditions,
+                                                                    boundary_conditions_parabolic))
+
+###############################################################################
+# ODE solvers, callbacks etc.
+
+tspan = (0.0, 1.0)
+ode = semidiscretize(semi, tspan)
+
+summary_callback = SummaryCallback()
+
+analysis_interval = 100
+analysis_callback = AnalysisCallback(semi, interval = analysis_interval,
+                                     extra_analysis_integrals = (entropy,))
+
+alive_callback = AliveCallback(analysis_interval = analysis_interval)
+
+save_restart = SaveRestartCallback(interval = 100,
+                                   save_final_restart = true)
+
+save_solution = SaveSolutionCallback(interval = 100,
+                                     save_initial_solution = true,
+                                     save_final_solution = true,
+                                     solution_variables = cons2prim)
+
+amr_controller = ControllerThreeLevel(semi, IndicatorMax(semi, variable = first),
+                                      base_level = 1,
+                                      med_level = 2, med_threshold = 0.05,
+                                      max_level = 3, max_threshold = 0.3)
+amr_callback = AMRCallback(semi, amr_controller,
+                           interval = 5,
+                           adapt_initial_condition = true,
+                           adapt_initial_condition_only_refine = true)
+
+callbacks = CallbackSet(summary_callback,
+                        analysis_callback, alive_callback,
+                        save_restart, save_solution,
+                        amr_callback);
+
+###############################################################################
+# run the simulation
+ode_alg = RDPK3SpFSAL49()
+sol = solve(ode, ode_alg;
+            dt = 1e-5, # solve needs some value here but it will be overwritten by the stepsize_callback
+            ode_default_options()..., callback = callbacks);

src/callbacks_step/amr.jl

@@ -634,6 +634,8 @@ function (amr_callback::AMRCallback)(u_ode::AbstractVector, mesh::P4estMesh,
                 partition!(mesh)
                 rebalance_solver!(u_ode, mesh, equations, dg, cache,
                                   old_global_first_quadrant)
+                @unpack parabolic_container = cache_parabolic
+                resize!(parabolic_container, equations, dg, cache)
             end
         end