| 摘要 |
<p>The element (26; 126) comprises a front layer (28), which is, at least in a region thereof, sound-permeable; a back layer (30), which is substantially sound-reflecting; and a honeycomb layer (32), which is sandwiched between the front layer (28) and the back layer (30), and defines a mesh structure having a plurality of hollow cells (34) bordering on one another. The cells (34) are provided to resonate within their side walls the sound waves entering through the front layer (28) and being diverted by the back layer (30). The element (26;126) further comprises a plasma actuator (38, 40, 42, 44; 38, 40, 142, 44) provided to generate in the cells (34) a plasma discharge (D) inducing a flow of ionized air particles (A) interacting with the sound waves coming from the front layer (28).</p> |
