{
  "challenge_id": "cymbal-bow-v1",
  "title": "Bowed bronze disk (paraboloidal shell) struck with a drum stick, geometrically nonlinear: radiated pressure",
  "version": 1,
  "output": {
    "type": "wav",
    "sample_rate_hz": 48000,
    "num_samples": 288000,
    "channels": 1,
    "sample_format": "float32",
    "signal": "acoustic pressure at the listener point from the Rayleigh-type integral of the normal acceleration over the top face",
    "signal_unit": "Pa",
    "signal_scale": 80.0
  },
  "playback": {
    "gain_db": 30,
    "note": "Suggested playback gain for listening; presentation only, not part of the deliverable."
  },
  "geometry": {
    "type": "shell-of-revolution",
    "mid_surface": "z = Z(r) = bow_height * (1 - r^2 / disk_radius^2), 0 <= r <= disk_radius",
    "thickness": "uniform, measured along the normal to the mid-surface",
    "hole": null
  },
  "parameters": {
    "disk_radius": 0.2032,
    "bow_height": 0.025,
    "h": 0.001,
    "E": 110000000000.0,
    "nu": 0.34,
    "rho": 8800.0,
    "sigma0": 1.1,
    "eta": 1.2e-08,
    "strike_x": 0.17272,
    "strike_y": 0.0,
    "strike_radius": 0.005,
    "strike_duration": 0.001,
    "strike_peak_force": 1000.0,
    "rho_air": 1.204,
    "c_air": 343.0,
    "listener_x": 0.06,
    "listener_y": 0.08,
    "listener_z": 0.5,
    "strike_normalization_m2": 2.385927e-05
  },
  "metrics": {
    "primary": "waveform_l2",
    "waveform_l2": {},
    "spectrogram_l2": {
      "window": "hann_periodic",
      "n_fft": 2048,
      "hop": 512
    }
  },
  "fields": {
    "format": "hdf5",
    "quantity": "normal displacement of the mid-surface, u . n, at the mid-surface point above each grid point; NaN outside the disk",
    "units": "m",
    "axes": [
      "t",
      "y",
      "x"
    ],
    "shape": [
      3001,
      61,
      61
    ],
    "frame_rate_hz": 1000,
    "dtype": "float32"
  },
  "reference_solution": null,
  "model": "saint-venant-kirchhoff"
}