Diagnostics For Multiple-phase Blast Flows
Free (open access)
R. G. Ames, M. J. Murphy, S. E. Groves & D. Cunard
Multiple-phase blast (MPB) flows are a class of multi-phase flows where there is a strong, unsteady shock interacting with a non-gas-phase material. These flows are most often produced by introducing a solid-phase particulate (usually a metal powder) into a standard high explosive formulation. The presence of the particulate dramatically alters the momentum and energy transport properties of the blast field and produces substantial difficulty in producing measurements of those phenomena. Standard, gas-phase-only measurements (e.g. pressure gauges) capture only a portion of the momentum and energy transport associated with the MPB flowfield. For this reason, novel diagnostic techniques have been developed to aid in the characterization of a family of MPB explosive formulations. A brief overview of three techniques is included in this paper: the Unconfined Momentum Trap (UMT), the Inverted Ballistic Pendulum (IBP), and the Confined Momentum Trap (CMT). The relevant theory behind each of these techniques is discussed along with likely measurement uncertainties. Keywords: multiphase flow, multiphase blast, blast diagnostics, particle-laden flows, dusty flow. 1 Introduction Multiphase flows are a general class of flows that have application in a number of areas, including dispersal of pollutants, turbomachinery, rocket engines, sprays and droplets, and, as presented here, in the blast fields produced by particle-laden explosives. The general class of multiphase flows has been studied theoretically under the construct of an equivalent continuum model (e.g. [1–2]). Using this approach the dispersed non-gas-phase particulate is treated as a continuous phase with an equivalent density, sound speed, and
multiphase flow, multiphase blast, blast diagnostics, particle-laden flows, dusty flow.