1{
2 "challenge_id": "cymbal2-crash-v1",
3 "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",
4 "version": 1,
5 "model": "cymbal2 shallow shell (MODEL.md)",
6 "output": {
7 "type": "wav",
8 "sample_rate_hz": 48000,
9 "num_samples": 336000,
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": "shell-of-revolution",
19 "mid_surface": "Z(r) = bow_height (1 - r^2/disk_radius^2) + bell_height/2 (1 + cos(pi r / bell_radius)) [r < bell_radius]",
20 "thickness": "h(r) = thickness_center for r <= bell_radius, linear from thickness_center at bell_radius to thickness_rim at disk_radius",
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 "bow_height": 0.025,
42 "bell_radius": 0.055,
43 "bell_height": 0.015,
44 "thickness_center": 0.0012,
45 "thickness_rim": 0.0007
46 },
47 "strikes": [
48 {
49 "t": 0.0,
50 "x": 0.07,
51 "y": 0.0
52 },
53 {
54 "t": 2.0,
55 "x": 0.1016,
56 "y": 0.0
57 },
58 {
59 "t": 4.0,
60 "x": 0.17272,
61 "y": 0.0
62 }
63 ],
64 "metrics": {
65 "primary": "spectrogram_l2",
66 "spectrogram_l2": {
67 "window": "hann_periodic",
68 "n_fft": 2048,
69 "hop": 512
70 },
71 "waveform_l2": {}
72 },
73 "fields": {
74 "format": "hdf5",
75 "quantity": "transverse displacement w(x, y, t) of the mid-surface; NaN outside the annulus",
76 "units": "m",
77 "axes": [
78 "t",
79 "y",
80 "x"
81 ],
82 "shape": [
83 3501,
84 61,
85 61
86 ],
87 "frame_rate_hz": 500,
88 "dtype": "float32"
89 },
90 "reference_solution": null
91}