2 "challenge_id": "cymbal2-flat-v1",
3 "title": "Flat bronze annulus of uniform thickness struck near the rim by a drum stick: radiated pressure",
4 "version": 1,
5 "model": "cymbal2 shallow shell (MODEL.md)",
6 "output": {
7 "type": "wav",
8 "sample_rate_hz": 48000,
9 "num_samples": 288000,
10 "channels": 1,
11 "sample_format": "float32",
12 "signal": "acoustic pressure at the listener point from the Rayleigh integral of the transverse acceleration over the shell",
13 "signal_unit": "Pa",
14 "signal_scale": 16.0,
15 "signal_scale_note": "provisional until the first solutions are published"
16 },
17 "geometry": {
18 "type": "flat",
19 "mid_surface": "Z(r) = 0",
20 "thickness": "h(r) = thickness",
21 "domain": "annulus hole_radius <= r <= disk_radius, both edges free"
22 },
23 "parameters": {
24 "disk_radius": 0.2032,
25 "hole_radius": 0.006,
26 "E": 110000000000.0,
27 "nu": 0.34,
28 "rho": 8800.0,
29 "sigma0": 1.1,
30 "eta": 1.2e-08,
31 "stick_mass": 0.02,
32 "stick_speed": 10.0,
33 "contact_stiffness": 1000000000.0,
34 "contact_exponent": 1.5,
35 "strike_radius": 0.005,
36 "rho_air": 1.204,
37 "c_air": 343.0,
38 "listener_x": 0.65,
39 "listener_y": 1.125,
40 "listener_z": 0.75,
41 "thickness": 0.001,
42 "strike_x": 0.17272,
43 "strike_y": 0.0
44 },
45 "metrics": {
46 "primary": "spectrogram_l2",
47 "spectrogram_l2": {
48 "window": "hann_periodic",
49 "n_fft": 2048,
50 "hop": 512
51 },
52 "waveform_l2": {}
53 },
54 "fields": {
55 "format": "hdf5",
56 "quantity": "transverse displacement w(x, y, t) of the mid-surface, including the rigid drift; NaN outside the annulus",
57 "units": "m",
58 "axes": [
59 "t",
60 "y",
61 "x"
62 ],
63 "shape": [
64 3001,
65 61,
66 61
67 ],
68 "frame_rate_hz": 1000,
69 "dtype": "float32"
70 },
71 "reference_solution": null
72}