Propagation of acoustic waves in a fluid-filled pipe with periodic elastic Helmholtz resonators Project supported by the National Natural Science Foundation of China (Grant Nos. 11372346, 51405502, and 51705529). |
Frequency-dependent STLs for cavity length lc = 0.2 m (solid line), 0.1 m (dash dot line), and 0.05 m (dotted line). |