A pulsed particle injection system for shock tube studies of powders

Shock tubes offer a unique method for studying high temperature properties and/or combustion of particulate. The particles are simply introduced into the shock tube prior to firing and are subsequently heated by gases behind the shock waves. For dilute particle systems, the temperature of the partic ulate rapidly equilibrates with that of the processed gas; the experimenter can then monitor the high temperature behavior of the particles until the event is quenched by the wave processes within the shock tube. However, eff ective delivery of particles into the shock tube is not a trivial task and a method that has been proven to be effective is the subject of this articl e. The injection system uses mass loadings much less than 1 g, produces a u niform cloud at the end of a shock tube, and can be tailored to operate wit h a variety of different particle types. This system has been used to study the high temperature optical properties of Al2O3 (Parker , 18th JANNAF Con ference, Monterey, CA, 1989; Rawlins , AIAA Conference, 1993) as well as th e ignition/combustion properties of boron (Rawlins , Joint Eastern and Cent ral States Technical Meeting of the Combustion Institute, 1993). (C) 2001 A merican Institute of Physics.