Figure 1
From: Sound Pressure Level Gain in an Acoustic Metamaterial Cavity
Amplification rate and sound pressure distribution:
(a) acoustic metamaterial cavity composed of double coiled up space like structures with unit cell size, a, of 1 cm used in this study; (b) three samples with progressively shorter path lengths, l, obtained by decreasing the flange length, w (0.7, 0.4, 0.2 cm); (c) experimental (lines with dots) and simulated (lines) sound level gains for samples 1, 2 and 3 with g = 1 cm; experimental peak frequency for each sample was f = 990, 1420 and 2880 Hz, respectively; white noise with a frequency range of 71 Hz – 5.65 kHz was used for signal generation; (d) experimental (lines with dots) and simulated (lines) sound level gains for sample 1 with g = 1, 2 and 3 cm; peak frequency for each case was 990, 741 and 621 Hz, respectively; (e) spatial distribution of pressure amplitude for samples 1, 2 and 3 at peak frequencies of 990, 1420 and 2880 Hz, respectively; (f) spatial distribution of pressure amplitude for sample 1 with g = 1, 2 and 3 cm at peak frequencies of 990, 741 and 621 Hz, respectively.
