Accession Number : ADA133004

Title :   Continued Study of Stick Propellant Combustion Processes.

Descriptive Note : Memorandum rept. Oct 81-Sep 82,


Personal Author(s) : Robbins,Frederick W ; Horst,Albert W

PDF Url : ADA133004

Report Date : Jul 1983

Pagination or Media Count : 51

Abstract : The interior ballistic performance of propelling charges employing perforated, unslotted stick propellant often cannot be simulated using either lumped-parameter or two-phase-flow models, the experimental maximum pressure being much higher than calculated. A continuation of studies, initiated in FY81, into this anomalous performance has provided experimental evidence that the major contributor to this increase in pressure is splitting of the propellant sticks, a consequence of higher local pressures inside the long perforations of the unslotted sticks. Second-order effects include erosive burning or coning at the ends of the perforations and augmented burning rates on the progressive interior surfaces caused by the locally increased pressure. Other observations: slotted stick propellant was not found to split inside the gun, though fracturing occurred as the long grains tried to follow gas streamlines upon exiting a short-barreled test fixture; short, unslotted stick propellant, like slotted stick propellant, did not split during the interior ballistic event, yet produced greater muzzle velocities than predicted; and, finally, the NOVA two-phase-flow interior ballistic code provided good simulations of flamespread and pressurization inside the perforation of long, unslotted stick propellant.

Descriptors :   *Interior ballistics, *Propelling charges, *Gun propellants, *Mechanical properties, *Combustion, Erosive burning, Firing tests(Ordnance), Muzzle velocity, Pressure measurement, Failure(Mechanics), Computerized simulation, Fracture(Mechanics)

Subject Categories : Ammunition and Explosives

Distribution Statement : APPROVED FOR PUBLIC RELEASE