Rapid formation of a shelter-in-place using a combination of vortex flow and chemical oxidation for indoor environments containing neurotoxic gases

Abstract Neurotoxic gases constitute a threat to the health of civilian population and military personnel, but the existing rescue methods are passive and inefficient. Therefore, a new method that combines vortex flow with chemical oxidation is proposed to remove neurotoxic gas and rapidly form a shelter-in-place in indoor environment. The concentration and velocity of the poisonous gas were calculated by Computational Fluid Dynamics (CFD) simulations and verified by Particle Image Velocimetry (PIV) experiments. The effects of mass ratio of gaseous oxide chemicals to poisonous gases, number of oxide inlets, velocity at inlet of the ventilation tube, and position of the pollution source on the volume of shelter and amount of poisonous gases over time were also investigated in order to clear poisonous gas and construct shelter as quickly as possible. The results show that the optimal conditions were as follows: mass ratio 2:1, numbers of oxide inlet 4, and the velocity at the inlet of ventilation tube 4 m/s, respectively. Moreover, the amount of poisonous gases and shelter formation time decreased with increase in mass ratio of gaseous oxide chemicals and the number of oxide inlets due to the influence of mass fraction ratio. Furthermore, the methodology is shown to be robust, because the amount of toxic gas was always less than LCt50 when the mass ratio was greater than 1:1, regardless of the source of toxic gas source location. This work provides a reference for rapid formation of shelters and quick rescue under neurotoxic gas attack in indoor environments.