20th Annual Student Research Conference
Science
Sound Transmission Through a One-Dimensional Periodic Filter With a Defect
James D. Lloyd
Dr. Ian Lindevald, Faculty Mentor
A periodic acoustical filter was created in which the number and size of repeated “cells” are adjustable. Earlier research using this system showed that band gap structures predicted by theory were easily verified experimentally in a variety of conditions. More recently, systems with breaks in the periodicity, known as defects, have been studied. Existing theory has been extended to make predictions for transmission through such systems, and these predictions have been verified experimentally. In general, the presence of a defect introduces narrow transmission peaks within the band gap regions. These “defect peaks” have widths that increase as the number of cells decreases. Ultimately, this system will be used to investigate supersonic group velocities for pulse transmission in the band gap region and subsonic group velocities for frequencies within the defect peak.
Keywords: Acoustics, Band Gaps, Defect Peak, Defect, Periodic Lattice, Wave Transmission, Acoustic Waveguide
Topic(s):Physics
Presentation Type: Oral Paper
Session: 47-2
Location: VH 1416
Time: 1:30 pm