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This viewgraph presentation is a personal reflection on the development of the monopropellant hydrazine thruster. There is discussion of the problems and the solutions encountered in the development process.
Several instruments have been developed to measure low concentrations of hydrazine but none are completely satisfactory. A brief review is presented of current instruments such as the electrochemical cell, the ion mobility spectrometer, the mass spectrometer, the gas chromatograph, and the electronic nose.
This paper will discuss in detail the preliminary design, analysis, and proof of concept tests with hydrazine that were performed with a crude catalyst bed to determine extent of the reaction.
Selenium (Se) has reemerged as a promising absorber material for indoor and tandem photovoltaics (PVs), and its alloys with Te (Se 1−x Te x ) offer a widely tunable bandgap. Solution processing of this materials system offers a route to low-cost fabrication. However, solution processing of Se has, thus far, only used hydrazine, which is an extremely hazardous solvent. In this work, we prepare and isolate propylammonium poly-Se and poly-Se–Te precursors from a safer thiol-amine solvent system. We formulate molecular inks by dissolving the precursor in dimethylformamide (DMF) with a monoethanolamine (EA) additive and process high-quality Se and Se 1−x Te x films with bandgaps ranging from 1.20 eV to 1.86 eV. We fabricate PVs from these films using TiO 2 and MoO 3 charge transport layers (CTLs) to achieve power conversion efficiencies as high as 2.73% for Se and 2.33% for Se 0.7 Te 0.3 under solar simulation. Se devices show excellent stability with no degradation after 1 month in air, enabled by the excellent stability of Se and the use of inorganic CTLs. This work represents an important step towards low-cost solution-phase processing of Se and Se 1−x Te x alloys for PVs and photodetectors with low toxicity and high bandgap tunability.
The results of an experimental program directed toward determining some of the operational characteristics of the nitrogen tetroxide-hydrazine propellant system under oxidizer-rich and fuel-rich conditions are reported. Data are presented for the mixture-ratio ranges of 0 to 0.55 at a nominal chamber pressure of 300 psia and characteristic chamber length of 250 in., and at mixture ratios of 5.9 to 13.0 at nominal chamber pressures of 400 and 500 psia and characteristic chamber lengths of 100 and 3900 in. The relationship of the actual performance data obtained in each region with those predicted from thermochemical performance calculations is presented. From this comparison, it is concluded that in neither region are equilibrium conditions obtained and that utilization of performance data obtained from assumptions of equilibrium will lead to serious errors. In the oxidizer-rich region investigated, temperatures considerably below those predicted occur throughout the range of mixture ratios investigated because of the lack of exothermic dissociation of the nitrogen oxides. In the fuel-rich region, below a mixture ratio of 0.3, temperatures considerably higher than those predicted occur because of the lack of endothermic dissociation of ammonia.
Hydrazine-nitrogen tetroxide rocket propellant reaction study
Stainless steel column is used in gas chromatographic analysis of propellant-grade hydrazine. The column has also been found effective for the separation of other amines and alcohols and nitriles.
Turbojet thrust augmentation with fuel-rich afterburning of hydrogen, diborane, and hydrazine
Computer programs used for formulating and solving integral and differential equations in study of catalytic reactors for hydrazine decomposition
Analytical study of catalyzed hydrazine decomposition reaction chambers for predicting system steady state and transient behavior
Injector-element physical size effect on mixing and combustion of nitrogen tetroxide-hydrazine propellants
Storability and thermal stability of solutions of 10 to 30 percent ammonium perchlorate in hydrazine
Computer program representing two dimensional steady state model of distributed-feed catalyzed hydrazine decomposition reaction chamber
Dual mode hydrazine system for attitude control and maneuvering propulsion of interplanetary space probe
Photographs, thermocouples, and emission spectra used to study mixing and reaction of hydrazine and nitrogen tetroxide
Small uncooled combustion chamber tests of performance and stability characteristics of nitrogen tetroxide-hydrazine propellant
Mathematical model and computer program of catalyzed hydrazine decomposition reaction chamber
Relative contributions of direct molecular elimination and radical disproportionation reactions to formation of nonrandomized nitrogen in photolysis of hydrazine