Add trixi participant to channel transport tutorial

channel-transport/README.md

@@ -28,6 +28,8 @@ Fluid participant:
 
 * Nutils. For more information, have a look at the [Nutils adapter documentation](https://www.precice.org/adapter-nutils.html). This Nutils solver requires at least Nutils v7.0.
 
+* Trixi. Required dependencies: [Trixi.jl](https://github.com/trixi-framework/Trixi.jl) (tested with v0.5.30), [OrdinaryDiffEq.jl](https://github.com/SciML/OrdinaryDiffEq.jl) (tested with v6.53.2), [PreCICE.jl](https://github.com/precice/PreCICE.jl) (tested with v2.5.0). Currently, Trixi uses Euler equations (not incompressible Navier-Stokes) and periodic boundary conditions in all directions.
+
 Transport participant:
 
 * Nutils. For more information, have a look at the [Nutils adapter documentation](https://www.precice.org/adapter-nutils.html). This Nutils solver requires at least Nutils v7.0.

channel-transport/fluid-trixi/fluid.jl

@@ -0,0 +1,138 @@
+
+using Downloads: download
+using OrdinaryDiffEq
+using Trixi
+using PreCICE
+
+###############################################################################
+# semidiscretization of the compressible Euler equations
+
+equations = CompressibleEulerEquations2D(1.4)
+
+function initial_condition_channel(x, t, equations::CompressibleEulerEquations2D)
+    rho = 1.0
+    rho_v1 = 1.0
+    rho_v2 = 0.0
+    rho_e = 10.0
+    return SVector(rho, rho_v1, rho_v2, rho_e)
+end
+
+initial_condition = initial_condition_channel
+
+solver = DGSEM(polydeg=2, surface_flux=flux_lax_friedrichs)
+
+###############################################################################
+# Create mesh
+
+coordinates_min = (0.0, 0.0) # minimum coordinates (min(x), min(y))
+coordinates_max = (6.0, 2.0) # maximum coordinates (max(x), max(y))
+
+# Create a uniformly refined mesh
+trees_per_dimension = (6, 2)
+mesh = P4estMesh(trees_per_dimension,
+                 polydeg=1, initial_refinement_level=1,
+                 coordinates_min=coordinates_min, coordinates_max=coordinates_max,
+                 periodicity=(true, true))
+                 # periodicity=(false, false))
+
+semi = SemidiscretizationHyperbolic(mesh, equations, initial_condition, solver,
+                                    # boundary_conditions=Dict(
+                                    #   :all => BoundaryConditionDirichlet(initial_condition)
+                                    # )
+                                   )
+
+
+###############################################################################
+# 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)
+
+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=1.0)
+
+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
+#             save_everystep=false, callback=callbacks);
+# summary_callback() # print the timer summary
+
+
+integrator = init(ode, CarpenterKennedy2N54(williamson_condition=false),
+                  dt=1.0, # solve needs some value here but it will be overwritten by the stepsize_callback
+                  save_everystep=false, callback=callbacks);
+
+##################################################################################
+
+
+commRank = 0
+commSize = 1
+
+
+PreCICE.createSolverInterface("Fluid", "../precice-config.xml", commRank, commSize)
+
+dimensions = PreCICE.getDimensions()
+
+
+meshID = PreCICE.getMeshID("Fluid-Mesh")
+
+dataID = PreCICE.getDataID("Velocity", meshID)
+
+
+numberOfVertices = nelements(solver, semi.cache)
+
+vertices = transpose(semi.cache.elements.node_coordinates[1:2,2,2,1:numberOfVertices])
+
+vertexIDs = PreCICE.setMeshVertices(meshID, vertices)
+
+
+writeData = zeros(numberOfVertices, dimensions)
+
+
+solver_dt = 0.005
+
+u = Trixi.wrap_array(integrator.u, semi)
+
+let # setting local scope for dt outside of the while loop
+
+    precice_dt = PreCICE.initialize()
+
+    while PreCICE.isCouplingOngoing()
+
+        dt = min(solver_dt, precice_dt)
+        step!(integrator, dt, true)
+
+        for i = 1:numberOfVertices
+            node_vars = Trixi.get_node_vars(u, equations, solver, 2, 2, i)
+            _, v1, v2, _ = cons2prim(node_vars, equations)
+            writeData[i, 1] = v1
+            writeData[i, 2] = v2
+        end
+
+        PreCICE.writeBlockVectorData(dataID, vertexIDs, writeData)
+
+        precice_dt = PreCICE.advance(dt)
+
+    end # while
+
+end # let
+
+summary_callback() # print the timer summary