Design and performance characterization of a sub-Newton N2O monopropellant thruster

Cai, Guobiao; Sun, Wei; Fang, Jie; Mao, Li; Ye, Cong; Yang, Zhe

doi:10.1016/j.ast.2011.10.003

Cited by 15 publications

(8 citation statements)

References 14 publications

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“…Catalytic decomposition of high concentration nitrous oxide (N 2 O) has been a topic of interest for decades, since it was crucial for ignition of N 2 O propellant for small satellite or abatement of N 2 O from adipic acid industry for emission control [1][2][3][4] . Decomposition of N 2 O into N 2 and O 2 is a strongly exothermic process ( r H o  -82 kJ/mol) with maximum temperature in the propulsion system or reactor exceeding 1000 o C [5][6][7] . Therefore, the qualified catalysts should combine the features of both high activity and thermal stability.…”

Section: Introductionmentioning

confidence: 99%

Sn promoted BaFeO3− catalysts for N2O decomposition: Optimization of Fe active centers

Huang

Zhu

Wang

et al. 2017

Journal of Catalysis

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A series of BaFe 1-x Sn x O 3-δ catalysts were prepared by sol-gel method and tested for N 2 O decomposition to shed light on the effect of B-site substitution on the catalytic behavior of perovskite catalysts. 119 Sn and 57 Fe Mössbauer results confirmed that the 5-fold coordinated Fe 3+ cations with one adjacent oxygen vacancy (Fe 3+-O 5) were the main active centers for N 2 O decomposition. Doping of Sn cations can significantly improve the percentage of Fe 3+-O 5 from 30% (x = 0) to 68% (x = 0.8). More importantly, the valence state of Fe could be gradually reduced due to weakening of Fe-O bond with increasing the Sn content, which was attributed to the stronger force of Sn than Fe in Fe-O-Sn structure to draw the oxygen anion and expansion of unit cell volume. Such change of Fe chemical state favored the oxygen mobility of the catalyst, leading to reduction of activation energy for N 2 O decomposition from ca. 241 (x = 0) to 178 kJ mol-1 (x = 0.8). BaFe 0.2 Sn 0.8 O 3-δ catalyst exhibited the highest intrinsic rate of 1.49 s-1 (550 o C), nearly 4 times larger than BaFeO 3-δ (0.43 s-1).

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Section: Introductionmentioning

confidence: 99%

Sn promoted BaFeO3− catalysts for N2O decomposition: Optimization of Fe active centers

Huang

Zhu

Wang

et al. 2017

Journal of Catalysis

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“…Nitrous oxide (N 2 O) is a compound which has been recognized as a greenhouse gas and ozone depletion agent, and anthropogenic emissions are being rigorously regulated. , Different from the N 2 O emissions as an environmental pollutant, high-concentration N 2 O (vol % = 30–100%) is considered to be a promising green propellant. This can be attributed to the nontoxicity and low-cost of N 2 O compared to the traditional hydrazine, as well as self-pressurization, good compatibility, and system simplicity. , The great potency of nitrous oxide for providing micropropulsion is based on the chemical decomposition into nitrogen and oxygen which can generate large amounts of heat (Δ H r 0 ≈ −82.5 kJ/mol). However, in view of the extreme operating conditions of N 2 O decomposition applicable in the propulsion systems ( T > 1000 °C, E a ≈ 250 kJ/mol), catalytic materials with high resistance to thermal shock are required to lower the initiation temperature and accelerate the decomposition rate .…”

Section: Introductionmentioning

confidence: 99%

Characterization of Fe Substitution into La-Hexaaluminate Systems and the Effect on N₂O Catalytic Decomposition

et al. 2014

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Compared to Ba-hexaaluminates with β-Al 2 O 3 structure, La-hexaaluminates with magnetoplumbite (MP) structure have more substituted Al sites in the preferentially exposed mirror plane, which should favor N 2 O decomposition. In this regard, LaFe x Al 12−x O 19 catalysts with x = 1 and 5 were herein prepared using the coprecipitation method. 57 Fe Mossbauer spectroscopy and X-ray diffraction structure refinements revealed that Fe 3+ ions originating in Fe 2 O 3 species mainly entered tetrahedral Al(2) and trigonal bipyramidal Al(5) sites. Meanwhile, Fe 3+ ions in octahedral sites of perovskite-type LaFeO 3 intermediates preferentially accommodated in octahedral Al(3) sites in the mirror plane of La-hexaaluminates. Correlation of normalized rates (moles of N 2 O per hour per square meter) of the catalysts at 500 °C with the occupancy of Fe ions in different Al crystallographic sites of the MP phase indicated that Fe 3+ ions in the Al(3) and Al(5) sites were highly active for N 2 O decomposition. In contrast, Fe 2+ derived from a Fe 3+ → Fe 2+ reduction under high-temperature calcination played a negative role.

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“…In small thruster facilities where output varies from a sub-Newton to a few Newton level, a vacuum pump is usually employed to evacuate the vacuum cell during its operations. This method is recommended due to the low evacuation load [4][5][6]. When evacuation load is high, the most appropriate method is to use a supersonic diffuser system which utilizes the exhaust flow momentum to reduce nozzle back pressure [1-3, 7, 8].…”

Section: Introductionmentioning

confidence: 99%

Analytical and experimental investigation of satellite thruster vacuum performance employing supersonic ejectors

Sultan

Khan

Omer

2018

J Braz. Soc. Mech. Sci. Eng.

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The present study is carried out to investigate the performance of a cold gas thruster operating under the vacuum with a high expansion ratio. A pressure recovery system employing diffuser and multistage ejectors is employed to evacuate a vacuum cell whose pressure is an indicating parameter of an operating altitude (i.e. nozzle exit condition). The cold gas thruster has an expansion area ratio of 60. For ejector design, the parameters like the length to diameter ratio (L/D e) and ejector nozzle stagnation pressure (P tot) seem to have significant importance, and their effects on vacuum cell pressure are studied by using both analytical and experimental techniques. Role of second throat type diffuser in the overall pressure recovery is also investigated. The required exit pressure is achieved by a two-stage ejector system having constant area mixing chambers. The ejectors' stagnation pressures are considered from 12 to 20 bars, while (L/D e) is considered from 4.5 to 15 and 2.5 to 16.5 for Ejector-1 and Ejector-2, respectively. Minimum vacuum cell pressure is achieved with the (L/D e) of 7 and 9 and stagnation pressure (P tot) of 18 and 20 bars for Ejector-1 and Ejector-2, respectively. The thrust coefficient (CF) and the specific impulse (Isp) were found in good agreement with the theoretical results.

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Design and performance characterization of a sub-Newton N2O monopropellant thruster

Cited by 15 publications

References 14 publications

Sn promoted BaFeO3− catalysts for N2O decomposition: Optimization of Fe active centers

Sn promoted BaFeO3− catalysts for N2O decomposition: Optimization of Fe active centers

Characterization of Fe Substitution into La-Hexaaluminate Systems and the Effect on N₂O Catalytic Decomposition

Analytical and experimental investigation of satellite thruster vacuum performance employing supersonic ejectors

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Design and performance characterization of a sub-Newton N2O monopropellant thruster

Cited by 15 publications

References 14 publications

Sn promoted BaFeO3− catalysts for N2O decomposition: Optimization of Fe active centers

Sn promoted BaFeO3− catalysts for N2O decomposition: Optimization of Fe active centers

Characterization of Fe Substitution into La-Hexaaluminate Systems and the Effect on N2O Catalytic Decomposition

Analytical and experimental investigation of satellite thruster vacuum performance employing supersonic ejectors

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Characterization of Fe Substitution into La-Hexaaluminate Systems and the Effect on N₂O Catalytic Decomposition