IGNITION AND FLAME PROPAGATION IN NARROW CHANNELS OF SOLID PROPELLANT: CONVENTIONAL VS. PLASMA IGNITION

摘要

Future direct-fire gun systems will likely face volume and weight constraints that require a propelling charge at high loading density. This can be achieved with solid propellant in slab-type geometries such as radial discs, concentric wraps or scrolls. Adjacent propellant slabs will form porosity as narrow sheet-like channels. It is important to characterize the ignition and transient combustion behavior within such channels. A special laboratory apparatus was designed to isolate two propellant channels and allow direct comparison of the influence of variable gap-width, wall composition (inert or JA2 here), and channel end closure. The ignition stimulus can be either conventional igniter gases or plasma generated from an electrical discharge. Diagnostics include multiple pressure time-histories along each channel length and high-speed cinematography of the propagation of flame. Results are presented for channel configurations involving combinations of JA2 propellant and plastic material at gap separations of 0.33 and 0.89 mm, along with differences in response from exposure to conventional igniter gases and plasma.