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 Ms, initial particle volume fraction φp, and particle size dp on the dimensionless streamwise average velocity vpx,a/us, velocity inhomogeneity ξvp and dispersity of particles ψp. 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. [ABSTRACT FROM AUTHOR]