NOVEL HIGH VELOCITY-FINE WATER MIST NOZZLE FOR AIRCRAFT FIRE SUPPRESSION

Water is an attractive halon-alternative extinguishing agent for fire suppression. This SBIR proposes to develop a twin-fluid water nozzle that produces spray with a Sauter Mean Diameter less than 20 microns, and discharges water droplets at high velocities (equivalent to 500 m/s) to enhance penetration and quench the fire. An inert gas such as nitrogen will be expanded through a supersonic nozzle. Water will be injected and sheared by the high velocity gas to produce a finely atomized spray. In Phase I, the nozzle feasibility will be demonstrated. The ideal location of water injection (i.e. in subsonic, sonic, or supersonic region) and the aerodynamic shape of the nozzle will be resolved. Advanced 2-D and 3-D CFD aerodynamic shape of the nozzle will be resolved. Advanced 2-D and 3-D CFD analysis of the gas and liquid will be used to design at least two candidate nozzles. Brass prototypes will be fabricated and tested at Southwest Research Institute (SwRI). In Phase II, the nozzle will be optimized and incorporated into a turnkey flame suppression system which will be developed in collaboration with subcontractor Zallen International Associates (ZIA). Fire protection and explosion suppression tests at SwRI will determine the sytem's overall effectiveness. In Phase III, the sytem will be aggressively marketed to aircraft manufacturers and other interested parties.