Modeling and Simulation of a Shock Driving Gas Jet Laden with Dense Extinguishant Particles Through a Tube with a Tail Nozzle

In this study, we proposed a new concept of shock wave driving fire extinguishing system (SWDES), which works using a pulsed shock-induced gas-particle jet. We conducted modeling and simulations of shock-induced gas-particle jets through a rectangular tube with a tail nozzle based on a dense discrete phase model. A corrected drag model was developed to take into account gas compressibility and particle volume fraction effects. The aerodynamic and collision forces imposed on particles were determined by a point particle force model and an improved spring-dashpot model, respectively. Based on the validation of numerical method against a previous experiment, a parametric study was performed to explore the effects of type of tail nozzle, incident shock Mach number M_s, initial particle volume fraction φ_p, and particle size d_p on the dimensionless streamwise average velocity v_px,a/u_s, velocity inhomogeneity ξ_vp and dispersity of particles ψ_p. We revealed that the evolution process of the gas-particle jet consists of the first transmitted shock-induced stage and the second pressure-induced stage of gas jet, and identified penetration, spreading and breakup types of pulsed gas-particle jets suited for fire suppression of correspondingly three types of flames.