flow123d_version: 4.0.0a01
problem: !Coupling_Sequential
  description: Test12 - demonstration of unstability of reaction solver without CFL condition (exact solution (50+5*exp(-55*t))/55)
  mesh:
    mesh_file: ../00_mesh/prism_3el.msh
  flow_equation: !Flow_Darcy_LMH
    input_fields:
      - rid: 1
        anisotropy: 1
      - region: .BOUNDARY
        bc_type: dirichlet
        bc_piezo_head: 0
    output:
      fields:
        - pressure_p0
        - velocity_p0
    nonlinear_solver:
      linear_solver: !Petsc
        a_tol: 1.0e-07
    output_stream:
      file: ./decay.pvd
      format: !vtk
        variant: ascii
  solute_equation: !Coupling_OperatorSplitting
    transport: !Solute_Advection_FV
      input_fields:
        - rid: 1
          init_conc:
            - 1
            - 0
        - region: .BOUNDARY
          bc_conc:
            - 1
            - 0
    output_stream:
      file: ./transport_decay.pvd
      format: !vtk
        variant: ascii
      times:
        - step: 2e+0
    substances:
      - A
      - B
    time:
      end_time: 10.0
    reaction_term: !FirstOrderReaction
      reactions:
        - reactants: A
          reaction_rate: 5
          products: B
        - reactants: B
          reaction_rate: 50
          products: A
    balance:
      cumulative: true
