The Bombardier Beetle Fire Extinguisher: Development of a CFD Model to Simulate a Novel Firefighting Mechanism

While modern fire extinguishers are adequate in extinguishing fires, they tend to have a short spray distance, a wide target area, and use chemicals that can harm humans. By creating a fire extinguisher that mimics the defense mechanism of the Bombardier Beetle, many of these downfalls can be corrected. When threatened, The Bombardier Beetle can facilitate a chemical reaction in its abdomen that builds pressure, eventually releasing the reactants at high velocities, high frequencies, and for long distances. This mechanism can be replicated in a fire extinguisher by vaporizing water in a pressure chamber. This would allow for fire to be fought from a safer distance, with a safer working fluid, and more effectively. To examine this effect, multiphase flow was simulated through an experimental chamber geometry using CFD. It was found that sufficient vaporization and pressure increase occurred to cause an increase in the velocity at the outlet. This proves that this technique can be viable as a mechanism in fire extinguishers. Various parameters of the model were modified to determine the presence of numerical diffusion. With the CFD model that minimizes numerical diffusion, pulsation, valve timing, and ejection mechanics should be investigated.