Measurement of Debris in the Flow from Pyrotechnic Reactions Using an Instrumented Hopkinson Pressure Bar

Abstract

When an NASA standard initiator (NSI) combusts within the confinement of a pyrovalve, debris is generated and entrained into flow. This debris can originate from the closure disc, the zirconium potassium percholate (ZPP) reactants, and perhaps material ablated from the valve body such as aluminum. Measurement of debris parameters such as velocity along with estimates of debris mass and resulting kinetic energy are important for understanding of the pyrovalve booster charge. An instrumented Hopkinson pressure bar can accurately measure the impacting degree as a function of time along with pressure time history at the booster location in the pyrovalve.