Experimental Study of Pressure Wave Propagation in Granular Propellant Bed

The ignition transients and penetrative burning characteristics of confined granular propellant beds in a cylindrical tube (loading densities up to 1.03 g cm3 and pressures up to 4000 bar) were investigated to test the 1-D pressure-wave propagation profiles predicted by the 1971 Kuo-Vichnevetsky-Summerfield analytical model. Thus, it was found that following the initial pressure rise along the bed, the position of peak pressure occurs within the bed and progresses downstream at an accelerating rate. The ignition time of the granular bed increases sharply with decreasing loading density. Wall friction acting on the unburned propellant along the tube attenuates downstream transmission of solid phase pressure generated by the upstream burning processes. This work has applications to the internal ballistics of guns, deflagration to detonation transition, and fast-burning rocket charges.