Physicomathematical Modeling of Explosive Dispersion of Liquid and Powders

Abstract

Studies have been conducted with respect to the generation of fine‐disperse aerosols with the use of an explosive disperser model based on hydrodynamic shock tube. The physicomathematical model for the process of explosive dispersion with the aforesaid design is described [1]. The use of elements in the model design to produce cavitation bubbles under the action of shock wave and ensurance of slower outflow process of a water‐steam mixture makes it possible to obtain liquid disperse aerosols.The experimental results for aerosol disperse parameters and the processes of initiation and propagation of an aerosol cloud produced upon explosive dispersion of a variety of liquids and condensed powders are presented. Pressure values in the combustion chamber of the disperser, velocity of aerosol particles, and aerosol disperse parameters were obtained.The design of the explosive disperser with a nozzle, which provides favorable conditions for cavitation processes inside the dispersed liquid, is shown to allow the generation of a high dispersity aerosol (about 1–100 nm), which is essential for many practical problems. The function of distribution of such particles by size cannot be measured reliably and directly by methods available; however, indirect experiments (measurement of humidity when dispersing water) permit estimating the existence of particles in the aerosol with sizes below 1 μm in quantity of approx. 90 %.

The role of cavitation in submicron aerosol dispersion

“…The both designs under question generate acoustic vibrations that create conditions for cavitation. Let us show, following the report [6], what droplet size one should expect in this case.…”

“…The aerosol generation process by using the impulse atomizer was considered earlier [6]. The triggered explosive charge produces a shock wave that translates into a series of resonant acoustic vibrations with wavelength λ=L and frequency c f L  .…”

“…The aerodynamic atomization has a theoretical limit on the size of the resulting droplets as a function of the jet outflow rate [5]. However, there is a possibility to produce fine aerosol even at moderate outflow velocities and energy inputs for atomization demonstrated by the example of an impulse aerosol generator powered by a high-energy material (HEM) [6]. It was shown that droplet' size could be reduced by the cavitation phenomenon in the impulse atomization as compared to aerodynamic atomization techniques.…”

Mathematical Model of Propagation of an Aerosol Created by an Impulse Method in Space

“…The proposed technique for decontaminating aerosol clouds utilizes a pulsed generation method, which was introduced in [ 13 , 14 , 15 ]. This method employs high-energy materials to rapidly spray powders or liquids into the atmosphere.…”

On firework blasts and qualitative parameter dependency

“…In this work, we do not consider detailed models for the interaction between the shock wave and the packed particles (e.g. [8][9][10][11]) nor the chemical aspects which are beyond the scope of this work. 1 We make the following simplifying assumptions:…”