Publication in: Spring 2024 Issue

Title:
Reduced Wave Speed in 3D Printed Corrugated Pipes
Author(s):
Halle Theriault
Author Email:
htheriau@unca.edu
Department:
PHYSICS & ASTRONOMY
Faculty Mentor(s):
James Perkins
Abstract / Summary:
As sound waves travel through a corrugated tube, the speed of sound is attenuated. This surprising but consequential phenomenon also occurs in "bumpy"--i.e., periodically perturbed--materials in the fields of electronics, solid-state physics, and optics--where, for example, it explains the refraction of light in water. Two different models can be used to explain this effect in acoustics: the Griffiths periodic wave theory and the Cummings suppressed mass model. However, the two models differ in their predictions of how the speed of sound varies with corrugation depth, width, and spacing. To test these two theories, the speed of sound was measured using 3D modeled and printed corrugated tubes which allowed for precise control of the corrugation parameters. Computational finite element analysis (FEA) supported our experimental results, which suggests that the Bloch theory underpredicts and the Cummings model overpredicts the speed reduction. Experimental results from the first set of nine tubes and FEA results will be helpful in creating a third model.
Publication Date:
May-14-2024
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