{
  "challenge_id": "cymbal2-crash-v1",
  "title": "Bowed, belled and tapered crash cymbal struck three times by a drum stick, on the bell, at half the radius and near the rim: radiated pressure",
  "version": 1,
  "model": "cymbal2 shallow shell (MODEL.md)",
  "output": {
    "type": "wav",
    "sample_rate_hz": 48000,
    "num_samples": 336000,
    "channels": 1,
    "sample_format": "float32",
    "signal": "acoustic pressure at the listener point from the Rayleigh integral of the transverse acceleration over the shell",
    "signal_unit": "Pa",
    "signal_scale": 16.0,
    "signal_scale_note": "provisional until the first solutions are published"
  },
  "geometry": {
    "type": "shell-of-revolution",
    "mid_surface": "Z(r) = bow_height (1 - r^2/disk_radius^2) + bell_height/2 (1 + cos(pi r / bell_radius)) [r < bell_radius]",
    "thickness": "h(r) = thickness_center for r <= bell_radius, linear from thickness_center at bell_radius to thickness_rim at disk_radius",
    "domain": "annulus hole_radius <= r <= disk_radius, both edges free"
  },
  "parameters": {
    "disk_radius": 0.2032,
    "hole_radius": 0.006,
    "E": 110000000000.0,
    "nu": 0.34,
    "rho": 8800.0,
    "sigma0": 1.1,
    "eta": 1.2e-08,
    "stick_mass": 0.02,
    "stick_speed": 10.0,
    "contact_stiffness": 1000000000.0,
    "contact_exponent": 1.5,
    "strike_radius": 0.005,
    "rho_air": 1.204,
    "c_air": 343.0,
    "listener_x": 0.65,
    "listener_y": 1.125,
    "listener_z": 0.75,
    "bow_height": 0.025,
    "bell_radius": 0.055,
    "bell_height": 0.015,
    "thickness_center": 0.0012,
    "thickness_rim": 0.0007
  },
  "strikes": [
    {
      "t": 0.0,
      "x": 0.035,
      "y": 0.0
    },
    {
      "t": 2.0,
      "x": 0.1016,
      "y": 0.0
    },
    {
      "t": 4.0,
      "x": 0.17272,
      "y": 0.0
    }
  ],
  "metrics": {
    "primary": "spectrogram_l2",
    "spectrogram_l2": {
      "window": "hann_periodic",
      "n_fft": 2048,
      "hop": 512
    },
    "waveform_l2": {}
  },
  "fields": {
    "format": "hdf5",
    "quantity": "transverse displacement w(x, y, t) of the mid-surface, including the rigid drift; NaN outside the annulus",
    "units": "m",
    "axes": [
      "t",
      "y",
      "x"
    ],
    "shape": [
      3501,
      61,
      61
    ],
    "frame_rate_hz": 500,
    "dtype": "float32"
  },
  "reference_solution": null
}