Friday, September 7, 2012 4:00 p.m. in ETC 4.150
Mustafa Z. Abbasi and Joelle I. Suits
Department of Mechanical Engineering
Applied Research Laboratories
The University of Texas at Austin
A trapped or injured firefighter in a burning building has a small window of time to escape safely. This seminar will present work underway to assist firefighters in these difficult situations using acoustics. Personal Alert Safety System (PASS) devices are currently used to signal the presence of a downed firefighter using an audible alarm. However, they do not always work effectively, and the nationally recognized standard for this technology allows for a range of signals. The purpose of this research is to establish a scientific basis for an optimized signal to be used throughout the U.S. fire service. The problem has been cast as a passive sonar problem, and historically, none of the terms used in the passive sonar equation for signal-to-noise ratio [SNR = SL ‑ TL ‑ (NL ‑ RC)] has been scientifically studied for this application. Here, research on the PASS source level (SL), fireground background noise level (NL) and the effect of other personal safety equipment on the receiver characteristics (RC) are presented. A concurrent study seeks to understand the effects of fire, temperature gradients and smoke on transmission loss (TL) within burning structures. Results of experiments using laboratory-scale turbulent diffusion flames will be presented. Finally, a proof-of-concept active sonar navigation system is under development using a parametric acoustic source. Initial results on the detection of room boundaries through flames will be presented.