Dual hierarchical particle jetting of a particle ring undergoing radial explosion

Abstract

We study experimentally the formation of a dual hierarchical jetting pattern in dry dense particle media subjected to the radially divergent shock loadings in a radial Hele-Shaw cell. The distinct internal and external jetting patterns were formed on the internal and external surfaces of a ring at different times, respectively. The former features dozens of radially aligned fine filaments. By contrast, the latter consists of a large number of small spikes. Once the internal jets are fully developed, a novel proportionate growth is observed, in which distinguishable structures of the overall pattern all grow at the same rate until the interaction between the internal and external jets becomes significant, leading to the inversion of the internal jetting pattern. Although the external jetting is found to be an instability of a Rayleigh-Taylor (RT) type, the internal jetting exhibits a much delayed onset and slower early-stage growth compared with the RT instability, indicating different underlying physics.

Riemann solver with internal reconstruction (RSIR) for compressible single-phase and non-equilibrium two-phase flows

“…As reported by Rodriguez et al (2013) and Xue et al (2018), instabilities appear first at the inner interface and second at the outer one. Shape of these fingers is singular, in the sense that they do not qualitatively compare to the Richtmyer-Meshov instabilities or Rayleigh-Taylor ones, nor any other known instability.…”

“…Typical results reported in Rodriguez thesis are shown in Figure IV.2 at times 5 ms, 8 ms and 57 ms after rupture of the shock tube diaphragm, inducing shock wave and gas flow through a ring of flour particles. Figure IV.2 -Typical interfacial instabilities reported in Rodriguez thesis and papers, as well as in Xue et al (2018). Impulsive motion of a particle ring by a gas flow induces well defined particles fingers flowing to the center direction, oppositely to the gas flow.…”

“…Experimental and numerical studies of this phenomenon have been achieved by Zhang et al (2001), Milne et al (2010), Frost (2010), Parrish and Worland (2010) to cite a few. Simplified situations have been considered in Rodriguez et al (2013) and Xue et al (2018). The explosive is replaced by a shock tube and the matter to disperse is placed between two plates, in a Hele-Shaw cell.…”

Numerical investigations of two-phase finger-like instabilities

“…Experimental and numerical studies of this phenomenon have been carried out by Zhang et al (2001) [1], Milne et al (2010) [2], Frost (2010) [3], Parrish and Worland (2012) [4], Osnes et al (2019) [5], Utkin (2019) [6] to cite a few. Simplified situations have been considered in Rodriguez et al (2013) [7] and Xue et al (2018) [8]. The explosive is replaced by a shock tube and the matter to disperse is placed between two plates, in a Hele-Shaw cell.…”

Heterogeneous/particle-laden blast waves

“…A convenient arrangement for visualizing the instabilities that develop when a layer of particles is dispersed by a shock is the 2D Hele-Shaw apparatus used by Rodriguez et al [15,25,26], as well as, more recently, by Xue et al [27]. They attached an air shock tube perpendicular to the center of a Hele-Shaw cell containing a ring of fine powder.…”