Hypergolic systems: A review in patents

Silva, Gilson da; Iha, Koshun

doi:10.5028/jatm.2012.04043812

Cited by 18 publications

(8 citation statements)

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“…Based on the pressure rise data in the injector manifolds, the fuel was injected slightly earlier than the oxidizer almost 28 ms, but the oxidizer-rich environment was immediately caused in the startup phase. It seems that the O/F mass ratio could be easily shifted toward to the oxidizerrich condition, considering that the mass flow rate and density of HTP were higher than those of the nontoxic hypergolic fuel; the densities of the oxidizer and fuel under the standard condition were 1410 and 952 kg∕m 3 , respectively. As a result, this undesirable startup condition could trigger the long ignition delay approximately for 640 ms. During the delay, the propellants were oversupplied, and a large quantity of the unreacted propellants were accumulated in the chamber.…”

Section: B Occurrence Of Hard Start With 90% High-test Peroxide Oxidmentioning

confidence: 99%

“…Furthermore, the combination of nontoxic hypergolic bipropellants should provide comparable or superior performance than the currently used toxic propellants. Considering these benefits of the nature of nontoxic hypergolic propellants, it is possible to develop a high-performance bipropellant thruster with an aim of faster development at low cost and with reduced risk [3,4]. From this perspective, many institutes around the world make efforts to enhance their capabilities in the field of green space propulsion.…”

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confidence: 99%

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Suppression of Hard Start for Nontoxic Hypergolic Thruster Using H2O2 Oxidizer

Kang

Lee

Kwon

2017

Journal of Propulsion and Power

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The present paper describes the phenomenon of hard start observed from a demonstrator of 500 N scale nontoxic hypergolic thruster using high-test peroxide as an oxidizer. When 90% concentration of hydrogen peroxide was used, the hard start was observed even under the fuel lead operation. To effectively suppress the occurrence of hard start phenomena in the startup phase of the thruster, oxidizer-to-fuel mass ratio and concentration of hydrogen peroxide have been individually considered. In drop tests, the ignition delays of hypergolic reactions became longer in the oxidizer-rich condition than those measured in the fuel-rich condition. By regulating oxidizer-to-fuel mass ratio with deliberate control of the oxidizer mass flow rate, the thruster operated smoothly even using 90% high-test peroxide in the fuel-rich environment. Furthermore, without the utilization of the flow control device, the thruster successfully operated when higher concentrations of high-test peroxide (95 and 98%) were used under the fuel-rich condition.

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Section: B Occurrence Of Hard Start With 90% High-test Peroxide Oxidmentioning

confidence: 99%

mentioning

confidence: 99%

Suppression of Hard Start for Nontoxic Hypergolic Thruster Using H2O2 Oxidizer

Kang

Lee

Kwon

2017

Journal of Propulsion and Power

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“…Hypergolic mixtures consist of two different substances that spontaneously ignite upon coming into contact at ambient conditions. One substance plays the role of a strong oxidizer (fuming HNO 3 , N 2 O 4 , H 2 O 2 , Cl 2 ), whereas the other one the role of the combustible fuel (aniline, nitrile rubber, hydrazine derivatives, ionic liquids, acetylene) [1][2][3][4][5][6]. Such reactions are often used in chemistry demonstrations to show the impressive power of chemical energy, as well as ways to exploit it in real life applications (e.g., rocket propellants and fuels).…”

Section: Introductionmentioning

confidence: 99%

Functional Carbon Materials Derived through Hypergolic Reactions at Ambient Conditions

et al. 2020

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Carbon formation from organic precursors is an energy-consuming process that often requires the heating of a precursor in an oven at elevated temperature. In this paper, we present a conceptually different synthesis pathway for functional carbon materials based on hypergolic mixtures, i.e., mixtures that spontaneously ignite at ambient conditions once its ingredients contact each other. The reactions involved in such mixtures are highly exothermic, giving-off sizeable amounts of energy; hence, no any external heat source is required for carbonization, thus making the whole process more energy-liberating than energy-consuming. The hypergolic mixtures described here contain a combustible organic solid, such as nitrile rubber or a hydrazide derivative, and fuming nitric acid (100% HNO3) as a strong oxidizer. In the case of the nitrile rubber, carbon nanosheets are obtained, whereas in the case of the hydrazide derivative, photoluminescent carbon dots are formed. We also demonstrate that the energy released from these hypergolic reactions can serve as a heat source for the thermal conversion of certain triazine-based precursors into graphitic carbon nitride. Finally, certain aspects of the derived functional carbons in waste removal are also discussed.

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“…Moreover, the ID time is defined as the time between the contact of liquid fuel and liquid oxidizer to appear the flame, which should be less than 100 ms [24]. Since hypergolic propellants systems do not need any ignition source, they are suitable for space programs [25].…”

Section: Introductionmentioning

confidence: 99%

Assessment of Physico‐Thermal Properties, Combustion Performance, and Ignition Delay Time of Dimethyl Amino Ethanol as a Novel Liquid Fuel

Pakdehi

Keshavarz

Akbari

et al. 2017

Propellants Explo Pyrotec

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Dimethyl amino ethanol (DMAE) contains both hydroxyl and amino functional groups, which may be introduced as a new liquid fuel with high safety and less toxicity with respect to common high performance liquid fuels. Physico‐thermal properties, combustion performance and ignition delay time of DMAE are compared with the usual high performance liquid fuels as well as ethanol and dimethylamine. Combustion performances of DMAE (specific impulse at sea level) with common liquid oxidizers including white fuming nitric acid (WFNA), inhibited red fuming nitric acid (IRFNA), nitrogen tetroxide (N2O4), hydrogen peroxide (H2O2), liquid oxygen (LOX), and the mixed oxides of nitrogen (MON) are also evaluated. Maximum and minimum specific impulses of DMAE are obtained with LOX (299.6 s) and WFNA (262.4 s), respectively. Maximum density‐specific impulse is obtained with DMAE‐N2O4 bipropellant. The ignition delay time of DMAE with several liquid oxidizers are measured with open cup test method. DMAE‐WFNA and DMAE‐IRFNA bipropellants are hypergolic where their ignition delay times are 26 and 42 milliseconds, respectively.

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Hypergolic systems: A review in patents

Cited by 18 publications

References 0 publications

Suppression of Hard Start for Nontoxic Hypergolic Thruster Using H2O2 Oxidizer

Suppression of Hard Start for Nontoxic Hypergolic Thruster Using H2O2 Oxidizer

Functional Carbon Materials Derived through Hypergolic Reactions at Ambient Conditions

Assessment of Physico‐Thermal Properties, Combustion Performance, and Ignition Delay Time of Dimethyl Amino Ethanol as a Novel Liquid Fuel

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