摘要:

AbstractEnergetic solid fuels composed of modified GAP (glycidyl azide polymer) propellants were formulated in order to obtain optimized combustion characteristics for variable flow ducted rockets. Burning rate in a primary combustor and the combustion efficiency in a secondary combustor were studied and evaluated as a function of the mixture ration of fuel and air. The energetic fuels consisting of – N3groups in its chemical structure burned very rapidly even though the combustion temperature was low when compared with conventional solid propellants for rockets. The pressure exponent of the burning rate was optimized to gain wide range of mass generation rate. The combustion gases generated in the primary combustor burned very efficiently in a secondary combustor. The effective specific impulse of the ducted rockets was obtained to be about 780

ISSN:0721-3115    

DOI:10.1002/prep.19910160202

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractSpectroscopic studies indicate that N,2,4,6‐tetranitro‐N‐methylaniline (tetryl) forms two charges transfer (CT) complexes with ethylenediamine (EDA) and these complexes show absorption maxima at 440 nm and 340 nm respectively. Both the complexes have 1:1 ratio of donor to acceptor. The formation constant and molar extinction coefficient for the complexes have been determined in acetonitrile as well as in ethanol and methanol to evaluate the effect of polarity. The initial complex (λmaxat 440 nm) undergoes transformation to a product complex (λmaxat 340 nm) when the EDA concentration is lowered. The product complex has been isolated and characterized by IR, UV spectroscopy, thermal analysis and X‐ray diffraction (XRD). The transformation of the initially formed CT complex to the product complex in solution has been found to obey first order kinetics. The formation of CT complex of tetryl with EDA has been succesfully used to develop a spectrophotometric method for the quantitative determination

ISSN:0721-3115    

DOI:10.1002/prep.19910160203

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractThe flammability limits and ballistic properties of composite fuel‐rich propellants were studied experimentally, using PBAN/AP propellant formulations. Higher pressure and AP contents as well as smaller AP particle size were found to promote sustained combustion and to increase burning rate. The addition of potassium perchlorate (KP) in place of AP increased the burning rate pressure exponent from about 0.3 to over 0.7 at optimum conditions. Ferric oxide and copper chromite catalysts caused an increase of the burning rate by a factor of 2, while the addition of aluminum powder at the expense of the fuel binder was found to have a remarkable effect on the burning rate with a maximum increase of as high as 5‐f

ISSN:0721-3115    

DOI:10.1002/prep.19910160204

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractTwo potential mechanisms are described which may result in uncontrolled ignition in liquid propellant regenerative guns. The two mechanisms are related to reverse burn in the injection orifice. One mechanism is associated with a poorly designed injection orifice, which may result in a low discharge coefficient, boundary layer separation, and flame holding in the orifice. The second mechanism is related to the response of the liquid propellant reservoir to the ignition pressure, which may excite pressure oscillations in the reservoir resulting in a reverse orifice pressure gradient. Both mechanisms may result in a reverse orifice burn or flash back to the reservoir.

ISSN:0721-3115    

DOI:10.1002/prep.19910160205

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractThe thermal decomposition process and combustion wave structure of azide polymer were studied to determine the parameters which control the burning rate. The azide polymer studied was 3‐azidomethyl‐3‐methyl oxetane (AMMO) which contains energetic –N3groups. From the experiments, it was found that the thermal decomposition process of AMMO consists of a two‐stage weight loss process: the first‐stage corresponds to an exothermic reaction which is caused by the scission of N‐N2bond, and the second‐stage corresponds to the decomposition of the remaining fragments. The burning rate of AMMO is approximately 50% of the burning rate of GAP propellant and is as high as that of conventional double base propellant. The heat feedback from gas phase to the burning surface increase with increasing pressure. The burning surface temperature and the heat of reaction at the surface decrease with incr

ISSN:0721-3115    

DOI:10.1002/prep.19910160206

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractHigh performance shaped charges require a perfect rotational symmetry and material homogenity. In order to obtain the desired geometry of a detonation wave the density distribution of the explosive, inside such a charge, must meet certain specifications and must be symmetric. This paper presents a finite element simulation of the pressing process of shaped charges implementing a recently developed material model. The calculated result agree well analytical solutions and experiments.

ISSN:0721-3115    

DOI:10.1002/prep.19910160207

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractX‐ray radiation damage has been employed as a controllable method for the generating of partial decomposition products in the energetic material RDX. X‐ray photoelectron spectra provided a real time measure of the developing chemistries during the accumulation of radition damage. Rates of NO2loss were identical at 20 °C and −50 °C However, strong variations in the product chemistry were observed. Nitroso, triazine and for the first time, nitrite ester nitrogen chemistries were observed from the solid RDX. Initial reaction steps are suggested in light of this and previously report

ISSN:0721-3115    

DOI:10.1002/prep.19910160208

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractThe sensitivity of liquid monopropellants is examined when subjected to compression ignition, including the case of purposeful sensitization with air bubbles; and frictional heating. The monopropellant is a hydroxylammonium nitrate (HAN)‐based propellant. Conditions are identified which will likely result in ignition from rapid compression. Ignition from frictional heating associated with hydroynamic flow is less certain, however attempts to model this phenomenon theoretically have been mad

ISSN:0721-3115    

DOI:10.1002/prep.19910160209

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

ISSN:0721-3115    

DOI:10.1002/prep.19910160210

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

ISSN:0721-3115    

DOI:10.1002/prep.19910160211

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY