Accession Number : ADA213317

Title :   Heats of Explosion at Low Pressure.

Descriptive Note : Final rept. Oct 86-Oct 88,

Corporate Author : ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Cohen, Arthur ; Miller, Martin S. ; Holmes, Hughes E. ; Huntley, Bonita A.

Report Date : AUG 1989

Pagination or Media Count : 39

Abstract : Recent difficulties with predicting ignition and flamespreading in gun simulators have been attributed to assumptions concerning the chemical heat release at low pressures used in the interior ballistic codes. This has generated interest in obtaining quantitative information on the chemical energy (E) released by propellant combustion at low pressures. An investigation was initiated to determine the feasibility of obtaining E from heat of explosion (HEX) experiments at low loading densities and varying levels of prepressurization. The degree of the correlation of HEX with flame characteristics (structure and burn rate) will be indicative of the value of these data for predicting gun performance. Heats of explosion were measured in a pressurized calorimeter bomb which contained a piezoelectric transducer. Calorimeter combustion products were analyzed by gas chromatography. Difficulties with ignition were encountered as initial pressures and loading densities were lowered. These difficulties exacerbated problems with reproducibility of HEX data and place lower limits on operating pressure in the calorimeters. Preliminary results indicate that if these difficulties can be overcome then measured HEX may be used to determine nonequilibrium values for E corresponding to partial heat release of propellants burning at low pressures. Such data may be useful for describing early pressurization transients in IB gun models. Keywords: Heat of explosion; Gun propellants; Propellant flames; Simulators. (KT)

Descriptors :   *BURNING RATE, *FLAMES, *GUN PROPELLANTS, *IGNITION, *SIMULATORS, BOMBS, CALORIMETERS, CHEMICAL AGENTS, CHEMICAL PROPERTIES, CHEMICAL REACTIONS, CODING, COMBUSTION, COMBUSTION PRODUCTS, CORRELATION, DENSITY, ENERGY, EXPLOSIONS, GAS CHROMATOGRAPHY, GUNS, HEAT, INTERIOR BALLISTICS, LIMITATIONS, LOW DENSITY, GUNNERY TRAINERS, LOW LEVEL, LOW PRESSURE, MATHEMATICAL MODELS, NONEQUILIBRIUM FLOW, PIEZOELECTRIC TRANSDUCERS, PRESSURIZATION, PROPELLANTS, RELEASE, REPRODUCIBILITY, TRANSIENTS, VALUE.

Subject Categories : Ammunition and Explosives
      Thermodynamics
      Operations Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE