This paper describes experimental research into the initiation and propagation of rotating detonation for liquid Nitrogen TetrOxide(NTO) and liquid MonoMethylHydrazine(MMH).An annular rocket-type combustor without noz...This paper describes experimental research into the initiation and propagation of rotating detonation for liquid Nitrogen TetrOxide(NTO) and liquid MonoMethylHydrazine(MMH).An annular rocket-type combustor without nozzle was designed to investigate detonation combustion. The propellants were injected through unlike impingement injectors. The combustion flame fronts and pressure waves were detected using optical diagnostics and dynamic pressure sensors,respectively. The propagation of rotating detonation was established spontaneously by increasing the mass flow rate of propellants. The velocity of propagation of the flame fronts and pressure waves was nearly equal and reaches supersonic speed. Two different detonation combustion patterns are present, single wave mode and double waves mode. And in double waves mode, the two detonation waves are always counter-rotating. The possibility of rotating detonation initiation in a combustor with nozzle was also checked. Stable rotating detonation can be initialized and sustained at similar operating conditions.展开更多
Two hydrophobic imidazolylidene-cyanoborane complexes were prepared by the introduction of{BH2 CN} into the molecular formula via treatment of imidazolium iodide and Na BH3 CN avoiding literature’s tedious and hazard...Two hydrophobic imidazolylidene-cyanoborane complexes were prepared by the introduction of{BH2 CN} into the molecular formula via treatment of imidazolium iodide and Na BH3 CN avoiding literature’s tedious and hazardous procedures. These two complexes were fully characterized using IR spectroscopy,1 H NMR and13C NMR spectroscopy and high-resolution mass spectrometer. The X-Ray structure of NHC-1 has been determined. NHC-2 was proved to be hypergolic with WFNA and displayed the attractive properties such as water immiscibility, wide liquid range（Tg= -22C）, short ignition delay time（13 ms）, high density（0.98 g/cm3）, good density impulse（r Isp, 347 s g cm-3）, showing the promising application potential as a fuel and an efficient fuel additive.展开更多
The advance of space technology is deeply affected by the breakthrough of high-performance fuels.Hypergolic ionic liquids(HILs)are one of the most potential fuels for bipropellant systems.However,high viscosity value ...The advance of space technology is deeply affected by the breakthrough of high-performance fuels.Hypergolic ionic liquids(HILs)are one of the most potential fuels for bipropellant systems.However,high viscosity value and low specific impulse of traditional N-based HILs limit their application.Recently,boron-based HILs with low viscosity become the new candidates,and their derivatives are also found to promote the hypergolicity as additives in HILs.Here,the synthesis,physical chemical properties and thermal performance of boron-based HILs and HILadditive system are reviewed.展开更多
This study focuses on the stepwise procedure involved in the development of a numerical model of a bi-propellant hypergolic chemical propulsion system using key features and performance characteristics of existing and...This study focuses on the stepwise procedure involved in the development of a numerical model of a bi-propellant hypergolic chemical propulsion system using key features and performance characteristics of existing and planned (near future) propulsion systems. The study targets specific impulse of 100</span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">N delivery performance of thrust chambers which is suitable for primary propulsion and attitude control for spacecraft. Results from numerical models are reported and validated with the Rocket Propulsion Analysis (RPA) computation concept. In the modelling process, there was proper consideration for the essential parts of the thruster engine such as the nozzle, combustion chamber, catalyst bed, injector, and cooling jacket. This propulsion system is designed to be fabricated in our next step in advancing this idea, using a combination of additive manufacturing technology and commercial off the shelf (COTS) parts along with non-toxic propellants. The two non-toxic propellants being considered are Hydrogen Peroxide as the oxidiser and Kerosene as the fuel, thus making it a low-cost, readily available and environmentally-friendly option for future microsatellite missions.展开更多
Liquid film cooling serves as a critical thermal protection mechanism in rocket thrusters.The interaction between oxidizer droplet,which is deposited from main-stream region of thrust chamber,and fuel film on the wall...Liquid film cooling serves as a critical thermal protection mechanism in rocket thrusters.The interaction between oxidizer droplet,which is deposited from main-stream region of thrust chamber,and fuel film on the wall inevitably influences cooling efficiency,which is poorly understood in existing research.This study exper-imentally investigated hypergolic reaction between white fuming nitric acid droplet and ionic liquid fuel film at elevated wall temperature Tw using synchronized high-speed and infrared thermography.Results show that reaction progresses through inertia-dominant spreading,mixing,and culminates in intense liquid-phase explo-sion(micro-explosion).An elevated Tw intensifies micro-explosion,increasing the risk of wall exposure and leading to the decline of cooling efficiency.Paradoxically,the increase in local film temperature inversely correlates with Tw,which is related to reduced explosion delay time.These findings first provide thermal and hydrodynamic data essential for the design of future thermal protection measures for small hyper-golic liquid rocket thrusters and offer theoretical basis for optimizing liquid film cooling systems in bipropellant propulsion architectures.展开更多
A series of asymmetric monoimidazolium dihydroboronium-based ionic liquids （ILs） were synthesized from amine-boranes. All the resulting ILs were fully characterized by 1H and 13C NMR, IR spectroscopy, elemental anal...A series of asymmetric monoimidazolium dihydroboronium-based ionic liquids （ILs） were synthesized from amine-boranes. All the resulting ILs were fully characterized by 1H and 13C NMR, IR spectroscopy, elemental analysis or high resolution mass spectrum. Compared with the symmetric bisimidazolium dihydroboronium-based ILs, these new ILs exhibited improved properties with shorter ignition delay times （IDs）, higher densities, and lower phase transition temperature showing the promising application potential as green propellants. A series of asymmetric monoimidazolium dihydroboronium-based ionic liquids （ILs） were synthesized from amine-boranes. All the resulting ILs were fully characterized by 1H and 13C NMR, IR spectroscopy, elemental anal- ysis or high resolution mass spectrum. Compared with the symmetric bisimidazolium dihydroboronium-based ILs, these new ILs exhibited improved properties with shorter ignition delay times （IDs）, higher densities, and lower phase transition temperature showing the promising application potential as green propellants.展开更多
文摘This paper describes experimental research into the initiation and propagation of rotating detonation for liquid Nitrogen TetrOxide(NTO) and liquid MonoMethylHydrazine(MMH).An annular rocket-type combustor without nozzle was designed to investigate detonation combustion. The propellants were injected through unlike impingement injectors. The combustion flame fronts and pressure waves were detected using optical diagnostics and dynamic pressure sensors,respectively. The propagation of rotating detonation was established spontaneously by increasing the mass flow rate of propellants. The velocity of propagation of the flame fronts and pressure waves was nearly equal and reaches supersonic speed. Two different detonation combustion patterns are present, single wave mode and double waves mode. And in double waves mode, the two detonation waves are always counter-rotating. The possibility of rotating detonation initiation in a combustor with nozzle was also checked. Stable rotating detonation can be initialized and sustained at similar operating conditions.
基金the financial support from the National Natural Science Foundation of China (Nos. 21372027, 21376252)
文摘Two hydrophobic imidazolylidene-cyanoborane complexes were prepared by the introduction of{BH2 CN} into the molecular formula via treatment of imidazolium iodide and Na BH3 CN avoiding literature’s tedious and hazardous procedures. These two complexes were fully characterized using IR spectroscopy,1 H NMR and13C NMR spectroscopy and high-resolution mass spectrometer. The X-Ray structure of NHC-1 has been determined. NHC-2 was proved to be hypergolic with WFNA and displayed the attractive properties such as water immiscibility, wide liquid range（Tg= -22C）, short ignition delay time（13 ms）, high density（0.98 g/cm3）, good density impulse（r Isp, 347 s g cm-3）, showing the promising application potential as a fuel and an efficient fuel additive.
基金support of the National Natural Science Foundation of China(21905069,21703218)the Shenzhen Science and Technology Innovation Committee(JCYJ20180507183907224 and KQTD20170809110344233)+1 种基金Economic,Trade and Information Commission of Shenzhen Municipality through the Graphene Manufacture Innovation Center(201901161514)Guangdong Province Covid-19 Pandemic Control Research Fund 2020KZDZX1220。
文摘The advance of space technology is deeply affected by the breakthrough of high-performance fuels.Hypergolic ionic liquids(HILs)are one of the most potential fuels for bipropellant systems.However,high viscosity value and low specific impulse of traditional N-based HILs limit their application.Recently,boron-based HILs with low viscosity become the new candidates,and their derivatives are also found to promote the hypergolicity as additives in HILs.Here,the synthesis,physical chemical properties and thermal performance of boron-based HILs and HILadditive system are reviewed.
文摘This study focuses on the stepwise procedure involved in the development of a numerical model of a bi-propellant hypergolic chemical propulsion system using key features and performance characteristics of existing and planned (near future) propulsion systems. The study targets specific impulse of 100</span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">N delivery performance of thrust chambers which is suitable for primary propulsion and attitude control for spacecraft. Results from numerical models are reported and validated with the Rocket Propulsion Analysis (RPA) computation concept. In the modelling process, there was proper consideration for the essential parts of the thruster engine such as the nozzle, combustion chamber, catalyst bed, injector, and cooling jacket. This propulsion system is designed to be fabricated in our next step in advancing this idea, using a combination of additive manufacturing technology and commercial off the shelf (COTS) parts along with non-toxic propellants. The two non-toxic propellants being considered are Hydrogen Peroxide as the oxidiser and Kerosene as the fuel, thus making it a low-cost, readily available and environmentally-friendly option for future microsatellite missions.
基金National Key Research and Development Programof China,Grant/Award Number:2021YFA0716201National Natural Science Foundation,Grant/Award Number:52236001。
文摘Liquid film cooling serves as a critical thermal protection mechanism in rocket thrusters.The interaction between oxidizer droplet,which is deposited from main-stream region of thrust chamber,and fuel film on the wall inevitably influences cooling efficiency,which is poorly understood in existing research.This study exper-imentally investigated hypergolic reaction between white fuming nitric acid droplet and ionic liquid fuel film at elevated wall temperature Tw using synchronized high-speed and infrared thermography.Results show that reaction progresses through inertia-dominant spreading,mixing,and culminates in intense liquid-phase explo-sion(micro-explosion).An elevated Tw intensifies micro-explosion,increasing the risk of wall exposure and leading to the decline of cooling efficiency.Paradoxically,the increase in local film temperature inversely correlates with Tw,which is related to reduced explosion delay time.These findings first provide thermal and hydrodynamic data essential for the design of future thermal protection measures for small hyper-golic liquid rocket thrusters and offer theoretical basis for optimizing liquid film cooling systems in bipropellant propulsion architectures.
基金the financial support from the Na- tional Natural Science Foundation of China （Nos. 21372027 and 21172203） and Prof. Zhang, Y. for the calculation of specific impulse （Explore 5.0 （6.02 version））.
文摘A series of asymmetric monoimidazolium dihydroboronium-based ionic liquids （ILs） were synthesized from amine-boranes. All the resulting ILs were fully characterized by 1H and 13C NMR, IR spectroscopy, elemental analysis or high resolution mass spectrum. Compared with the symmetric bisimidazolium dihydroboronium-based ILs, these new ILs exhibited improved properties with shorter ignition delay times （IDs）, higher densities, and lower phase transition temperature showing the promising application potential as green propellants. A series of asymmetric monoimidazolium dihydroboronium-based ionic liquids （ILs） were synthesized from amine-boranes. All the resulting ILs were fully characterized by 1H and 13C NMR, IR spectroscopy, elemental anal- ysis or high resolution mass spectrum. Compared with the symmetric bisimidazolium dihydroboronium-based ILs, these new ILs exhibited improved properties with shorter ignition delay times （IDs）, higher densities, and lower phase transition temperature showing the promising application potential as green propellants.
