A multiphase shock tube for shock wave interactions with dense particle fields

Abstract

Currently there is a substantial lack of data for interactions of shock waves with particle fields having volume fractions residing between the dilute and granular regimes. To close this gap, a novel multiphase shock tube has been constructed to drive a planar shock wave into a dense gas-solid field of particles. A nearly spatially isotropic field of particles is generated in the test section by a gravity-fed method that results in a spanwise curtain of spherical 100-micron particles having a volume fraction of about 20%. Interactions with incident shock Mach numbers of 1.66, 1.92, and 2.02 are reported. High-speed schlieren imaging simultaneous with high-frequency wall pressure measurements are used to reveal the complex wave structure associated with the interaction. Following incident shock impingement, transmitted and reflected shocks are observed, which lead to differences in particle drag across the streamwise dimension of the curtain. Shortly thereafter, the particle field begins to propagate downstream and spread. For all three Mach numbers tested, the energy and momentum fluxes in the induced flow far downstream are reduced about 30-40% by the presence of the particle field.

Heterogeneous/particle-laden blast waves

“…In particular, they have shown that for dense particle clouds, important effects to account for during the shock interaction include the two-way coupling between the particles and gas, the particle inertia, and unsteady forces. When a planar shock wave interacts with a planar particle layer within a shock tube, the thickness of the particle layer increases in the longitudinal direction, whereas the layer surfaces remain relatively stable in the transverse direction [16,17]. In contrast, systems involving the interaction between a decaying blast wave and a cylindrical or spherical particle layer are more susceptible to the generation of instabilities at the surfaces of the particle layer.…”

“…Particle jets are formed as the fragments move radially outwards, and shed particulate in their wakes (d). Figure adapted from Loiseau et al [18] Recent experiments by Wagner et al [16] within a multiphase shock tube have provided a well-characterized dataset for the validation of the physical processes that occur during the shock interaction with a dense array of particles in air. Ling et al [17] have demonstrated that the processes associated with the shock interaction with a dense particle curtain differ significantly from those in a dilute gas-particle mixture.…”

Discrete element method prediction of particle curtain properties

“…There has been success in modeling these flows when the solid phase is in either the di-5 lute (Drew, 1983;Magnaudet and Eames, 2000;Crowe et al, 2012) or densely packed (Baer and Nunziato, 1986;Powers et al, 1990) regimes. However, the modeling of compressible flows when the solid phase has a volume fraction between these extremes has lagged behind (Wagner et al, 2012). Additionally, this intermediate regime of multiphase flows has seen relatively little experi-10 mental investigation due to the difficulties in isolating and measuring the high solid volume fraction regions.…”

“…A recent experiment has been developed that successfully isolates this multiphase flow regime by investigating the interaction between a shock wave and a dense non-compacted particle curtain (Wagner et al, 2012). The particle cur-15 tain used in this experiment is generated by the granular flow of glass beads through a hopper with a slit opening.…”

The flexible asymmetric shock tube (FAST): a Ludwieg tube facility for wave propagation measurements in high-temperature vapours of organic fluids

“…Examples include shock tubes for the study of non-equilibrium vapour condensation (Maerefat et al 1989), droplet condensation in expansion tubes (Peters and Rodemann 1998) and studies of particle-dense flow fields (Wagner et al 2012).…”