Physics of ADN combustion

Зенин, А. А.; Пучков, В. М.; Finjakov, S. V.

doi:10.2514/6.1999-595

Cited by 17 publications

(29 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is known that for the combustion without blowing, this is the case for a large number of EMs [9,10], which have been studied up to now by different researchers using microthermocouple measurements (the only exceptions are RDX and HMX at low pressures). In particular, the measurement results of [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] suggest an important role of subsurface heat release at typical rocket pressures for ballistite powders, monopropellants (including RDX, HMX, ADN, HNF, and CL-20), and composite propellants. At the same time, it can be assumed that at a fairly high blowing velocity, combustion is converted to gasification, which depends only on the heat transfer from the flow core and practically does not depend on the subsurface heat release in the condensed phase.…”

Section: Erosive Burning Of Ems With Significant Subsurface Heat Releasementioning

confidence: 99%

Erosive burning. Modeling problems

Gusachenko

Зарко

2007

Combust Explos Shock Waves

View full text Add to dashboard Cite

Existing models for the erosive burning of homogeneous energetic materials ignore the fact that the burning regime can be changed radically by exposure to a hot gas blowing over the burning surface. In other words, transition can occur from the gasification regime at very high blowing rates (where the burning rate is determined primarily by the heat transfer from the flow core) to the self-heating regime of the condensed phase at low or zero blowing if the heat release in the condensed phase is sufficient to heat it to the surface temperature. A possible method for solving this problem is proposed. The approach proposed provides a plausible explanation for the experimentally observed singular (kinked) dependence of the magnitude of the negative erosion effect on the initial temperature.

show abstract

Section: Erosive Burning Of Ems With Significant Subsurface Heat Releasementioning

confidence: 99%

Erosive burning. Modeling problems

Gusachenko

Зарко

2007

Combust Explos Shock Waves

View full text Add to dashboard Cite

show abstract

“…As it follows from the calculations, the experimental data of [9,10,21] on the location of the hightemperature flame zone with respect to the burning surface for different pressures are adequately reproduced in calculations if the kinetic mechanism [15] is applied. The location of the high-temperature zone with respect to the burning surface can be effectively controlled by small variations of the rate constants of stage Nos.…”

Section: Flame Structure In the Case Of Homogeneous Compositions On Tmentioning

confidence: 83%

“…The calculated structure of reaction zones remains qualitatively similar for different pressures; the results are compared with the experimental data of [9,10] at p = 3-41 atm in [14,16]. The calculated profiles of temperature in ADN flame in the range p = 5-60 atm are compared with the experimental curves [9,21] in Figs. 10-12.…”

Section: Flame Structure In the Case Of Homogeneous Compositions On Tmentioning

confidence: 92%

“…10-12. The experimental values of T s [21] are 613, 618, 628, 641, and 651 K for p = 5, 10, 20, 40, and 60 atm, respectively. The parameter varied in calculations was the rate constant K 15 = 8 · 10 5 T 1.05 exp(−700/RT ).…”

Section: Flame Structure In the Case Of Homogeneous Compositions On Tmentioning

confidence: 99%

“…The disbalance in terms of elements is within 6%. The enthalpy of the mixture calculated for T s taken from [21] ranges from −281 to −264 kcal/kg. The experimental values of T s in [21] are smaller and the temperature jump near the burning surface is greater than those in [9].…”

Section: Flame Structure In the Case Of Homogeneous Compositions On Tmentioning

confidence: 99%

See 2 more Smart Citations

Heat-release mechanism in ammonium dinitramide flame

Ermolin

2007

Combust Explos Shock Waves

View full text Add to dashboard Cite

To verify the adequacy of various models of heat release in ammonium dinitramide flame to real processes, chemical processes in products of thermal decomposition at a pressure of 10 torr and in ammonium dinitramide [ADN; NH 4 N(NO 2 ) 2 ] flame at a pressure of 0.4 to 60 atm are numerically simulated. The calculations are performed on the basis of a detailed kinetic mechanism and boundary conditions correlated with experimental data, thermodynamic properties, and chemical composition of ADN. The kinetic mechanism includes submechanisms that describe high-temperature chemical processes in NH 3 /N 2 O/NO/NO 2 /HNO 2 /HNO 3 and NH 3 /HN(NO 2 ) 2 mixtures, and the global stages of aerosol decomposition. Based on calculated and experimental data, the role of dinitraminic acid HN(NO 2 ) 2 , aerosols, and ADN vapor in heat release in the ADN flame zone adjacent to the burning surface is estimated. The calculations predict that the main source of heat release in the cold flame zone at p 3 atm is dinitraminic acid incoming through the channel of dissociative evaporation ADN liq → NH 3 + HN(NO 2 ) 2 from the burning surface. In the high-temperature flame zone, heat release is caused by the reaction that occurs in the NH 3 /N 2 O/NO/NO 2 /HNO 2 /HNO 3 mixture. At moderate pressures, the hightemperature and low-temperature zones are separated by an induction zone. The stage governing production of the OH radical, which plays an important role in combustion, in the induction zone is the reaction HNO 3 + M → OH + NO 2 + M. Because of a high activation energy of the stage, small temperature perturbations in the induction zone at low pressures lead to a finite change in the stand-off distance between the high-temperature flame zone and the burning surface. Therefore, small temperature perturbations in the induction zone, which are caused by admixtures in the sample or by heat transfer between the reacting gas and the ambient medium, may be responsible for disagreement between various experimental data and between experimental and calculated data on the stand-off distance between the high-temperature flame zone and the burning surface. In numerical calculations, the position of the hightemperature zone is effectively controlled by varying rate constants of elementary stages within admissible limits.

show abstract

Condensed Phase Behavior in the Combustion of Ammonium Dinitramide

Fujisato

Habu

Hori

2014

Propellants Explo Pyrotec

View full text Add to dashboard Cite

This paper reports on the thermal and combustion behaviors of ammonium dinitramide (ADN). The thermal behavior is measured by a pressure thermogravimetric analysis (TGA) at pressures below 8 MPa. The burning rates of pure ADN and ADN/ammonium nitrate (AN) mixtures are measured in the range 0.2-12 MPa, and the burning temperature profiles are obtained using thermocouples with diameters of 5 and 25 mm. This report mainly focuses on the condensed-phase behavior in the vicinity of a burning sur-face. The temperature profiles are complicated because the ADN decomposition and AN dissociation compete during the condensed phase, and the bubbles of the decomposition gas and gas-phase flame also affect the surface temperature. AN addition helps to understand the effects of AN during the condensed phase, and it was shown that the burning temperature rises to the critical temperature of AN. Based on these experimental results, the pressure dependency of the burning rates is also discussed.

show abstract

Physics of ADN combustion

Cited by 17 publications

References 0 publications

Erosive burning. Modeling problems

Erosive burning. Modeling problems

Heat-release mechanism in ammonium dinitramide flame

Condensed Phase Behavior in the Combustion of Ammonium Dinitramide

Contact Info

Product

Resources

About