A sonar experiment to study sound propagation through flames

Abstract

Disorientation is a major cause of firefighter death and injury. When a firefighter is trapped in a structure, there is a small window of time for rescue teams to locate a downed firefighter. We propose an acoustic navigation system based on sonar concepts to augment existing techniques (e.g. thermal imaging cameras). As a first step toward this system, a better understanding of acoustic wave propagation through the fire environment is needed. Therefore, a sonar experiment was developed to measure the distance through a flame. Since information in the literature suggests that transmission loss through fire increases with frequency, a parametric array was used to maintain narrow source directivity while remaining in the low frequency/low attenuation regime. Results of the sonar experiment will be presented for various source functions and flame conditions.