trixi-framework / Trixi.jl / 21638916092

# The same setup as tree_3d_dgsem/elixir_euler_source_terms.jl

# to verify the StructuredMesh implementation against TreeMesh

using OrdinaryDiffEqLowStorageRK

using Trixi

###############################################################################

# semidiscretization of the compressible Euler equations

equations = CompressibleEulerEquations3D(1.4)

initial_condition = initial_condition_convergence_test

# Up to version 0.13.0, `max_abs_speed_naive` was used as the default wave speed estimate of

# `const flux_lax_friedrichs = FluxLaxFriedrichs(), i.e., `FluxLaxFriedrichs(max_abs_speed = max_abs_speed_naive)`.

# In the `StepsizeCallback`, though, the less diffusive `max_abs_speeds` is employed which is consistent with `max_abs_speed`.

# Thus, we exchanged in PR#2458 the default wave speed used in the LLF flux to `max_abs_speed`.

# To ensure that every example still runs we specify explicitly `FluxLaxFriedrichs(max_abs_speed_naive)`.

# We remark, however, that the now default `max_abs_speed` is in general recommended due to compliance with the 

# `StepsizeCallback` (CFL-Condition) and less diffusion.

solver = DGSEM(polydeg = 3, surface_flux = FluxLaxFriedrichs(max_abs_speed_naive),

               volume_integral = VolumeIntegralWeakForm())

# coordinates_min = (0.0, 0.0, 0.0)

# coordinates_max = (2.0, 2.0, 2.0)

cells_per_dimension = (4, 4, 4)

mesh = StructuredMesh(cells_per_dimension, (f1, f2, f3, f4, f5, f6))

semi = SemidiscretizationHyperbolic(mesh, equations, initial_condition, solver,

                                    source_terms = source_terms_convergence_test)

###############################################################################

# ODE solvers, callbacks etc.

tspan = (0.0, 5.0)

ode = semidiscretize(semi, tspan)

summary_callback = SummaryCallback()

analysis_interval = 100

analysis_callback = AnalysisCallback(semi, interval = analysis_interval)

alive_callback = AliveCallback(analysis_interval = analysis_interval)

save_solution = SaveSolutionCallback(interval = 100,

                                     save_initial_solution = true,

                                     save_final_solution = true,

                                     solution_variables = cons2prim)

stepsize_callback = StepsizeCallback(cfl = 0.6)

callbacks = CallbackSet(summary_callback,

                        analysis_callback, alive_callback,

                        save_solution,

                        stepsize_callback)

###############################################################################

# run the simulation

sol = solve(ode, CarpenterKennedy2N54(williamson_condition = false);

            dt = 1.0, # solve needs some value here but it will be overwritten by the stepsize_callback

            ode_default_options()..., callback = callbacks);