We investigate experimentally and analytically the combustion behavior of a high-metal magnesium-based hydro- reactive fuel under high temperature gaseous atmosphere. The fuel studied in this paper contains 73% magnes...We investigate experimentally and analytically the combustion behavior of a high-metal magnesium-based hydro- reactive fuel under high temperature gaseous atmosphere. The fuel studied in this paper contains 73% magnesium powders. An experimental system is designed and experiments are carried out in both argon and water vapor atmo- spheres. It is found that the burning surface temperature of the fuel is higher in water vapor than that in argon and both of them are higher than the melting point of magnesium, which indicates the molten state of magnesium particles in the burning surface of the fuel. Based on physical considerations and experimental results, a mathematical one-dimensional model is formulated to describe the combustion behavior of the high-metal magnesium-based hydro-reactive fuel. The model enables the evaluation of the burning surface temperature, the burning rate and the flame standoff distance each as a function of chamber pressure and water vapor concentration. The results predicted by the model show that the burning rate and the surface temperature increase when the chamber pressure and the water vapor concentration increase, which are in agreement with the observed experimental trends.展开更多
For achieving high-speed requirement of underwater vehicle,a conceptual engine,which utilizes the hydroreactive characteristic of several metals under supercavitation environment,has been put forward. Especially,in or...For achieving high-speed requirement of underwater vehicle,a conceptual engine,which utilizes the hydroreactive characteristic of several metals under supercavitation environment,has been put forward. Especially,in order to obtain specific impulse as great as possible,a dual water injection system is taken into account. Then thermodynamic cycle model,which lead the improvement of power plant and energy system,is introduced in detail,and thermal efficiency is also analyzed. Furthermore,for investigating the performance of this kind of engine system,detailed thermodynamic calculation and analysis are achieved. Especially,regarding hydroreactive metal fuel Mg/AP/HTPB as our target fuel-rich propellant,considering its obvious deficient oxygen property and the energy property of magnesium/water reaction,theoretical calculation method is established by integrating chemical non-equilibrium with chemical equilibrium. Accordingly,low limit of primary water/fuel ratio is determined. In addition,the qualitative and quantitative relationship of performance parameters,such as theoretical specific impulse,nozzle exit temperature,characteristic velocity,etc.,versus water/fuel ratio is investigated respectively.展开更多
Experiments were conducted to determine the effects of the mixing section configurations on the Mg-CO_(2)Martian ramjet combustion efficiency.It was carried out at a mainstream mass flow rate of 110 g/s and a temperat...Experiments were conducted to determine the effects of the mixing section configurations on the Mg-CO_(2)Martian ramjet combustion efficiency.It was carried out at a mainstream mass flow rate of 110 g/s and a temperature of 810 K.The chamber pressure was measured under different configurations and Oxidizer to Fuel(O/F)ratios.Results showed that the engine achieved self-sustaining combustion and worked stably during experiments.The pre-combustion chamber is needed to increase the combustion efficiency and promote the full combustion of the powder.After the configuration of the pre-combustion chamber,the best combustion efficiency reached 80%when radial powder injection and lateral carbon dioxide intake were used.In addition,the O/F ratio in the pre-combustion chamber decreased from 0.67 to 0.31,resulting in an 8%increase in the combustion efficiency.It was speculated that different mixing section configurations and the variations in an O/F ratio within the pre-combustion chamber impacted the combustion efficiency and in essence,all affected the flow velocity and residence time of the two-phase flow in the com-bustion chamber.展开更多
基金Project supported by the Young Scientist Fund of the National Natural Science Foundation of China(Grant No.51006118)
文摘We investigate experimentally and analytically the combustion behavior of a high-metal magnesium-based hydro- reactive fuel under high temperature gaseous atmosphere. The fuel studied in this paper contains 73% magnesium powders. An experimental system is designed and experiments are carried out in both argon and water vapor atmo- spheres. It is found that the burning surface temperature of the fuel is higher in water vapor than that in argon and both of them are higher than the melting point of magnesium, which indicates the molten state of magnesium particles in the burning surface of the fuel. Based on physical considerations and experimental results, a mathematical one-dimensional model is formulated to describe the combustion behavior of the high-metal magnesium-based hydro-reactive fuel. The model enables the evaluation of the burning surface temperature, the burning rate and the flame standoff distance each as a function of chamber pressure and water vapor concentration. The results predicted by the model show that the burning rate and the surface temperature increase when the chamber pressure and the water vapor concentration increase, which are in agreement with the observed experimental trends.
基金Supported by National Natural Science Foundation of China (No .50776070)New Teacher Research Support Program of Xi an Jiaotong University (No .0106-08142002)
文摘For achieving high-speed requirement of underwater vehicle,a conceptual engine,which utilizes the hydroreactive characteristic of several metals under supercavitation environment,has been put forward. Especially,in order to obtain specific impulse as great as possible,a dual water injection system is taken into account. Then thermodynamic cycle model,which lead the improvement of power plant and energy system,is introduced in detail,and thermal efficiency is also analyzed. Furthermore,for investigating the performance of this kind of engine system,detailed thermodynamic calculation and analysis are achieved. Especially,regarding hydroreactive metal fuel Mg/AP/HTPB as our target fuel-rich propellant,considering its obvious deficient oxygen property and the energy property of magnesium/water reaction,theoretical calculation method is established by integrating chemical non-equilibrium with chemical equilibrium. Accordingly,low limit of primary water/fuel ratio is determined. In addition,the qualitative and quantitative relationship of performance parameters,such as theoretical specific impulse,nozzle exit temperature,characteristic velocity,etc.,versus water/fuel ratio is investigated respectively.
基金supported by the Fund of Advance Research Projects of Manned Spaceflight,China(No.050303).
文摘Experiments were conducted to determine the effects of the mixing section configurations on the Mg-CO_(2)Martian ramjet combustion efficiency.It was carried out at a mainstream mass flow rate of 110 g/s and a temperature of 810 K.The chamber pressure was measured under different configurations and Oxidizer to Fuel(O/F)ratios.Results showed that the engine achieved self-sustaining combustion and worked stably during experiments.The pre-combustion chamber is needed to increase the combustion efficiency and promote the full combustion of the powder.After the configuration of the pre-combustion chamber,the best combustion efficiency reached 80%when radial powder injection and lateral carbon dioxide intake were used.In addition,the O/F ratio in the pre-combustion chamber decreased from 0.67 to 0.31,resulting in an 8%increase in the combustion efficiency.It was speculated that different mixing section configurations and the variations in an O/F ratio within the pre-combustion chamber impacted the combustion efficiency and in essence,all affected the flow velocity and residence time of the two-phase flow in the com-bustion chamber.
