摘要:

AbstractFast thermolysis studies of ammonium nitrate (AN) and its mixtures with magnesium and activated charcoal have been carried out by the Fourier transform infrared spectroscopy/temperature profiling technique. When subjected to rapid heating (ca. 80°C/s), AN Sublimes/decomposes around 300°. Sublimation dominates at ambient pressures. The IR‐active products of decomposition are NH3, NO2, N2O and H2O. Reaction schemes accounting for the products are proposed which involve proton transfer leading to NH3by the decomposition products of HNO3. The decomposition of AN is significantly enhanced when AN is mixed with magnesium powder or charcoal, and occurs at as low a temperature as 135°C. Whereas NH3is the major product of decomposition of ANMg mixtures, no NH3is observed from ANC mixtures. The results are explained by the reaction of HNO3and NH3with

ISSN:0721-3115    

DOI:10.1002/prep.19920170302

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThermal behaviour of HMS/RDX mixtures is studied by differential thermal analysis (DTA) and thermogravimetric analysis (TGA). It has been found that the temperature of polymorphic transformation of HMX shows an increase due to the presence of RDX. The enthalpies of the enothermic transformations depend on the composition of the mixture, and up to 30% RDX there is a linear relationship. The formation of an eutectic with a composition of 30/70 (HMX/RDX) is postulated to explain the melting processes.

ISSN:0721-3115    

DOI:10.1002/prep.19920170303

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractA theoretical approach to the possibility of estimation of the heat development rate and heat accumulation rate until self‐ignition, is presented. Gun powder was thermally degradated until self‐ignition occures at several different temperatures in the vessels of different sizes. A microcalorimeter of the specific type was constructed for the detection of the thermal effects of the chemical degradation in the vessels of different sizes. T was measured for gun powder and for inert samples. Kinetics was calculated, and the obtained parameters were used for determination of the critical conditions of self‐ignition. In addition, diagrams are given for the time to self‐ignition determination even in the cases when critical conditions have not yet been a

ISSN:0721-3115    

DOI:10.1002/prep.19920170304

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThe electronic structures of dimethylnitramine (DMNA) were calculated using ab initio Gaussian 80 program at the Hartree‐Fock level with STO‐3G and STO‐4‐21G basis set, respectively. The Mulliken bond order of the NNO2bond is the least one in comparision with those of the other bonds in the DMNA molecule. Two potential energy curves along the NN bond splitting pathway (RNN) were obtained using MINDO/3 and MNDO methods, respectively. These curves have the same trend and are qualitatively consistent with the results obtained from the thermolysis of nitromethane (CH3NO2). It was found that the frontier MO levels and the net charges of groups are changed with RNNdistance. The products of thermal decomposition and the energy changes were calculated by MINDO/3 method and are discusse

ISSN:0721-3115    

DOI:10.1002/prep.19920170305

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractVulnerability studies are very important for rocket motors development using high energy and minimum smoke solid propellant. Among the treated threats, the bullet impact is a well known test studied for many years. Nevertheless, during our experimentations against true rocket motor, the well‐known scenarios failed. A new scenario has been identified and confirmed to take into account the new phenomenon. This scenario implied the solid propellant but also the geometry of the grain. The paper presents the experimental works and describes the physics of the phenomenon supported by the associated model studie

ISSN:0721-3115    

DOI:10.1002/prep.19920170306

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractA tower‐type drop‐weight tester is used to characterize mechanical properties of LOVA gun propellants ata nominal strain rate of 300 s−1. This study is a comparative evaluation of two testing methods, namely the original and the newly introduced one, that differ in the initial experimental setup. The results of the evaluation show that with the original testing method, the specimens are strained nonlineraly which, at times, has led to an anomalous compressibility reduction of the specimen. The newly introduced testing method improves the strain rate control and uniformity in addition of having a very good results‐reproduction cap

ISSN:0721-3115    

DOI:10.1002/prep.19920170307

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractRecent studies have clearly indicated that an electothermal chemical (ETC) gun provides many advantages over solid and liquid propellant guns. However, the interior ballistic process of an ETC gun has not yet been fully investigated. Specifically, the effects of the energy ratio between the electrical and chemical energy input on gun performance is not well understood. Nor is it known exactly how chemical energy is converted to propulsive energy during the ETC gun event. In view of this, a comprehensive theoretical model taking into full account electrical/chemical energy input, liquid entrainment process, distribution of dispersed droplets, and liquid propellant combustion, is developed to simulate the interior ballistics of an ETC gun. Governing equations are formulated from first principles for five different regions, including the gas phase (i.e., Taylor cavity), working fluid (i.e., liquid propellant), dispersed droplets, projectile, and plasma generation cartridge (PGC). Various energy ratios with two different PFN discharge characteristics are employed to evaluate ETC gun performance. Results indicate that the gun champer pressure, muzzle velocity, and ballistic efficiency depend strongly on the energy ratio. The electrical energy input and chemical energy release processes show unequal influence on the gun performance over different stages of ETC gun event. The predicted time history of the breech presure is compared with the measured breech pressur available in the literature. The results show that shapes of the breech pressure‐time traces and values of the peak pressure predicted by the present model agree reasonably well with the experimental dat

ISSN:0721-3115    

DOI:10.1002/prep.19920170308

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThe paper presents the results of a detailed technical investigations of the cause of the fire and subsequent explosion at Peterborough on 22 March 1989 involving a vehicle containing a mixed load of explosives and detonators.Tests were done to examine the sensitivenes and thermal stability of items of the load, and the behaviour of packaged explosives using drop, vibration and fire tests. Communication testing was undertaken with boxes of detonators, and ignition tests with boxes of fuseheads provided information relating to the characteristics of the fireballs generated.From analysis of the scientific data obtained, we conclude that the initial fire resulted from ignition of fusehead combs which were being transported in unauthorized and unsafe packaging, and we suggest a mechanism for detonatino involving the functioning of strewn detonators on fire‐damaged boxes of explosive

ISSN:0721-3115    

DOI:10.1002/prep.19920170309

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThe scheme for the compatibility assessment of materials with cast double base propellants as operated at Royal Ordnance Summerfield is described. Central to the scheme is the recognition that evaluation of the compatibility of materials must consider two areas of safety. These are on‐site process safety requirements, and rocket motor service life which includes safe chemicalstability and the long term functioning and reliability of a store. To rationalize testing, a system of compatibility testing to defined categories classified by the application and usage of a material is followe

ISSN:0721-3115    

DOI:10.1002/prep.19920170310

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY

ISSN:0721-3115    

DOI:10.1002/prep.19920170311

出版商:WILEY‐VCH Verlag GmbH    

年代:1992

数据来源: WILEY