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The scattering of sound by objects with dynamic deformations
1Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom.
The Journal of the Acoustical Society of America
|October 2, 2020
Summary
This study analytically solves sonic scattering from time-varying surfaces, revealing multi-frequency scattering and nonreciprocity from moving objects. Numerical simulations validate these findings across audio and ultrasonic frequencies.
Area of Science:
- Acoustics
- Wave physics
- Materials science
Background:
- Sonic scattering from rigid surfaces is a fundamental problem in acoustics.
- Understanding time-varying surfaces presents unique challenges due to dynamic boundary conditions.
Purpose of the Study:
- To analytically solve the sonic scattering problem for arbitrarily shaped, time-varying rigid surfaces.
- To investigate multi-frequency scattering and nonreciprocity phenomena.
- To establish a theoretical framework for Floquet scattering.
Main Methods:
- Perturbation theory for analytical solutions.
- Full-wave simulation using the finite-element method for numerical verification.
- Analysis across audio to ultrasonic frequency ranges.
Main Results:
- Demonstrated multi-frequency scattering from single moving objects.
- Observed and validated nonreciprocity due to spinning components.
- Developed theory for multiple Floquet scattering of sound.
Conclusions:
- The perturbation theory approach accurately models sonic scattering from time-varying surfaces.
- The study confirms nonreciprocal acoustic phenomena in dynamic systems.
- The developed Floquet scattering theory provides a basis for future research in tunable acoustic materials and devices.
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