Nitrous oxide(N_(2)O)is a green propellant with excellent application prospects.A subNewton N_(2)O monopropellant thruster with inner-heater and a N_(2)O self-pressurization stable supply system with regenerative heat...Nitrous oxide(N_(2)O)is a green propellant with excellent application prospects.A subNewton N_(2)O monopropellant thruster with inner-heater and a N_(2)O self-pressurization stable supply system with regenerative heat compensation are designed in this paper.The experimental research of the thruster is described,including measurements of preheating power,activation temperature,vacuum thrust,specific impulse,life-span and pulsed operation performance.By inserting the heater into the catalyst-bed,preheating efficiency of the heater is significantly improved compared to the thruster with outer-heater.Thus,the preheating power demand of the thruster is successfully reduced to around 10 W.The mean vacuum thrust of 322 mN is attained and the corresponding specific impulse reaches 162s at the mass flow rate of 0.2 g/s.Successful activation temperature of 523 K is achieved,and the activation performance of the thruster is affected by the loading factor.A long term hot-firing test longer than 12000 s is attained.The pulsed operation performance of the inner-preheating thruster is also studied by measuring chamber pressure.Impulses with different magnitudes are produced by adjusting the opening duration of the control valve.A minimum impulse of 81 mN·s is attained.Finally,the performance of the thruster is evaluated by comparison with other thrusters of the same type.The results indicate that the proposed thruster with inner-heater is superior in terms of preheating power,activation temperature and specific impulse performance.展开更多
The laminar burning velocity belongs to the fundamental combustion properties of fuels being a measure for their heat release,flame length,as well as reactivity and combustion stability,and thus,may impact the design ...The laminar burning velocity belongs to the fundamental combustion properties of fuels being a measure for their heat release,flame length,as well as reactivity and combustion stability,and thus,may impact the design of burners and combustion chambers.Also,these experimental data are needed for the validation and optimization within the construction and development of detailed chemical kinetic reaction mechanisms.Within this study,an overview of the different applications of fuel characterization regarding the specific area of interest(road transport,aviation,and aerospace)will be given.Depending on the application,effects of different molecular characteristics on the laminar burning velocity are evaluated:the presence of oxygen atoms and the grade of branching in a specific fuel molecule as well as the difference in the type of a chemical bond,here,single and double bonds.Examples of alternative fuels being discussed in the present study are:(Ⅰ)oxymethylene ether(OMEn)in the field of road transport;(Ⅱ)a paraffinic Alcohol-to-Jet fuel as sustainable aviation fuel;and(Ⅲ)mixtures of ethane or ethene with nitrous oxide as green propellants for rocket propulsion applications.展开更多
文摘Nitrous oxide(N_(2)O)is a green propellant with excellent application prospects.A subNewton N_(2)O monopropellant thruster with inner-heater and a N_(2)O self-pressurization stable supply system with regenerative heat compensation are designed in this paper.The experimental research of the thruster is described,including measurements of preheating power,activation temperature,vacuum thrust,specific impulse,life-span and pulsed operation performance.By inserting the heater into the catalyst-bed,preheating efficiency of the heater is significantly improved compared to the thruster with outer-heater.Thus,the preheating power demand of the thruster is successfully reduced to around 10 W.The mean vacuum thrust of 322 mN is attained and the corresponding specific impulse reaches 162s at the mass flow rate of 0.2 g/s.Successful activation temperature of 523 K is achieved,and the activation performance of the thruster is affected by the loading factor.A long term hot-firing test longer than 12000 s is attained.The pulsed operation performance of the inner-preheating thruster is also studied by measuring chamber pressure.Impulses with different magnitudes are produced by adjusting the opening duration of the control valve.A minimum impulse of 81 mN·s is attained.Finally,the performance of the thruster is evaluated by comparison with other thrusters of the same type.The results indicate that the proposed thruster with inner-heater is superior in terms of preheating power,activation temperature and specific impulse performance.
文摘The laminar burning velocity belongs to the fundamental combustion properties of fuels being a measure for their heat release,flame length,as well as reactivity and combustion stability,and thus,may impact the design of burners and combustion chambers.Also,these experimental data are needed for the validation and optimization within the construction and development of detailed chemical kinetic reaction mechanisms.Within this study,an overview of the different applications of fuel characterization regarding the specific area of interest(road transport,aviation,and aerospace)will be given.Depending on the application,effects of different molecular characteristics on the laminar burning velocity are evaluated:the presence of oxygen atoms and the grade of branching in a specific fuel molecule as well as the difference in the type of a chemical bond,here,single and double bonds.Examples of alternative fuels being discussed in the present study are:(Ⅰ)oxymethylene ether(OMEn)in the field of road transport;(Ⅱ)a paraffinic Alcohol-to-Jet fuel as sustainable aviation fuel;and(Ⅲ)mixtures of ethane or ethene with nitrous oxide as green propellants for rocket propulsion applications.
