# 2D Rayleigh-Taylor Instability (compressible two-phase 5eq, FV)
#
# Heavy fluid over light fluid with a perturbed interface and gravity.
# This is a smoke/regression setup intended to validate:
# - 2D two-phase Euler execution path
# - optional gravity source via physics.gravity.enabled
# - directional BCs (x periodic, y reflective)

domain:
  x_min: 0.0
  x_max: 1.0
  n_points_x: 96
  y_min: 0.0
  y_max: 1.0
  n_points_y: 192

time:
  dt: 1.0e-4
  n_steps: 6000

physics:
  mode: euler

  # Phase 1: heavy fluid
  phase1:
    name: heavy
    gamma: 1.4
    p_infinity: 0.0
    rho_ref: 2.0

  # Phase 2: light fluid
  phase2:
    name: light
    gamma: 1.4
    p_infinity: 0.0
    rho_ref: 1.0

  two_phase_model: 5eq
  euler_spatial_discretization: fv
  flux_calculator: hllc
  use_muscl: false

  # Directional BCs for 2D Euler
  euler_bc_x: periodic
  euler_bc_y: reflective

  # Modular gravity source (toggle enabled true/false)
  gravity:
    enabled: true
    gx: 0.0
    gy: -400.0

  # RTI initial condition
  euler_initial_conditions:
    type: rti
    interface_y0: 0.5
    alpha1_top: 1.0
    alpha1_bottom: 0.0
    perturbation_amplitude: 0.02
    perturbation_mode_x: 1
    interface_thickness: 0.003
    p0: 4.0e2
    u0: 0.0
    v0: 0.0

output:
  directory: ./unit_tests/rayleigh_taylor_2d
  monitors:
    - type: console

    - type: gif
      field: alpha
      every_n_steps: 315
      style: contour
      contour_levels: [0.5]
      contour_color: white
      background_color: "#2563eb"

    - type: gif
      field: rho
      every_n_steps: 315
      style: pcolormesh
      vmin: 0.9
      vmax: 2.1

    - type: txt
      fields: [rho, u, v, p, alpha]
      every_n_steps: 100