Zero-g acoustic fire suppression system

Abstract

The objective is to study the effects of acoustics on a flame in microgravity. This research is meant to provide a new approach to reducing and extinguishing a combustion reaction in space (where a conventional fire extinguisher is hazardous). The group proposes to test the following hypotheses: (1) as sound intensity increases, so does the magnitude of the effect on the flame; (2) there is one optimal frequency for maximizing the effects of sound waves on a flame; (3) homogeneous flames (found only in microgravity) can be affected in a single area separate from others; (4) a sustained pulse of sound, rather than a single, brief pulse, can be used to extinguish a flame. The group will describe the experimental apparatus in detail, which was flown aboard a NASA C-9B Aircraft through their Reduced Gravity Student Flight Opportunities Program (RGSFOP), and present the findings and compare data obtained in a 1-g environment with data collected in a microgravity environment. [Thanks to the following organizations for their support: Kicker Audio, Georgia Space Grant Consortium, Siemens, FLIR Systems, PCB Piezotronics, UWG Honors College, and NASAs Reduced Gravity Student Flight Opportunities Program.]

Acoustic Flame Suppression Mechanics in a Microgravity Environment

“…With the exception of equipment failure during a trial at 74 Hz there are no anomalies in the data, and only raw data is shown. Previous experiments involving acoustic flame suppression suggest that there exists optimal surface interactions at two frequencies with methane gas, one low frequency at roughly 30 Hz and another higher frequency at about 90 Hz (DARPA 2008;Plaks et al 2005) (Figs. 4 and 5) .…”

“…All programming was done using institutional resources and the GoPro Hero cameras are set as reference for aid in the analysis. Numerical simulations indicate a horizontal velocity induced in the flame and displacement of the flame tip as a result of the acoustic wave (Plaks et al 2005) , therefore both primary cameras are set in positions perpendicular to the direction of the propagation for analysis and for validation of visual data.…”