Temperature Gradients Controlled Broadband Acoustic Omnidirectional Absorber

F. Qian[1], L. Quan[1], X. Liu[1]
[1]Institute of Acoustics and School of Physics, Nanjing University, Nanjing, China
Published in 2014

Previous research into acoustic omnidirectional absorber (AOA) has shown the feasibility of forming acoustic black hole to guide the incident wave into the central absorptive cavity. However, major restrictions to practical applications exist due to complexity of designing metamaterials and unchangeable working states. Here, we propose two cylindrical, two-dimensional AOA schemes based on temperature gradients for airborne applications. One scheme with accurately designed temperature gradients has better absorption performance which can almost completely absorb the incident wave, while the other one with simplified configuration has low complexity which is much more easily to realize. Both schemes are temperature-tuned with broad working bandwidth.

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