Day: September 3, 2014

ME-EM Graduate Seminar: From carbon nanotubes to crowd noise: An overview of interesting topics in acoustics

barnardThe ME-EM Graduate Seminar speaker on Thursday, September 4 at 4:00 in 103 EERC will be Dr. Andrew Barnard, Mechanical Engineering – Engineering Mechanics, Michigan Technological University.

The title of his presentation will be ‘From carbon nanotubes to crowd noise: An overview of interesting topics in acoustics’.

Carbon nanotube (CNT) thin-films are ultra-lightweight, semi-transparent, flexible, and stretchable, films that can create sound through thermoacoustics. CNT thermophones have the potential to replace moving coil transducers and expand the applications of modern loudspeakers through “singing” fabrics. The fundamentals of CNT thermophone operation and key research challenges will be presented.
Underwater acoustics encompasses many disciplines and applications from Navy ships to oil exploration to climate change. Michigan Tech is located in an ideal location, on the shores of Lake Superior, to perform experimental underwater acoustics research through the Great Lakes Research Center (GLRC). Several topics in underwater acoustics will be discussed.
Transducer arrays and wavenumber domain signal processing provide a powerful way to visualize acoustic fields. An overview of techniques including supersonic intensity in reverberant environments (SIRE), and wavenumber processing of panel-to-panel transmission loss will be discussed. Current panel transmission loss (TL) measurement standards are woefully inadequate. Several test facilities can test the same specimen and the results can vary by more than 6 dB. Although panel TL theory is well developed, understanding of the fundamental measurement error is not. Insight into the field diffusivity in the source room will be discussed as well as paths towards an improved measurement standard. Smart controls systems are leading the way towards the realization of cyber-physical systems. An overview of the utility of FPGA-based control systems will be presented. These systems are particularly well suited for safety-critical control applications. Crowd noise is a much discussed topic in the mainstream media. Unfortunately most of the ad-hoc measurements that have been promoted are lacking in scientific rigor. Sound level measurements from Penn State football games will be presented to demonstrate how we can better measure this interesting phenomenon.

Dr. Andrew Barnard is a new assistant professor in the ME-EM department at Michigan Tech. He holds a B.S. and M.S. in mechanical engineering from MTU and a Ph.D. in Acoustics from Penn State. Dr. Barnard is Board Certified by the Institute for Noise Control Engineering and is a Certified LabVIEW Developer.
He spent the last 8 years working as a research faculty member at the Applied Research Laboratory at Penn State, specializing in structural acoustics. Dr. Barnard has general interests in mechanical vibration, noise control, and acoustics.
His specialties include dynamic test and measurement, underwater acoustic intensity, experimental modal analysis, room acoustics, acoustic material characterization, outdoor sound propagation, theoretical acoustics, signal processing, and real-time control systems. Other interests include loudspeaker design and fabrication, architectural acoustics, and engineering education.