Miniaturized Spiral Metamaterial Array for a Ventilated Broadband Acoustic Absorber

Figure 1

(a) The 3D-printed product for the varied-unit spiral array. (b) The corresponding 3D prototype model of (a). (c) The horizontal cross section and detailed dimensions of (a). (d) The 3D-printed product for the same spiral unit array. (e) The corresponding 3D prototype model of (d) but with the middle spiral reversed. (f) The horizontal cross section of (e).

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