Space systems design (spacecraft, satellites, space stations and their equipment)
Alireza Rajabi; Noordin Qadiri Massoom; Mohammadali Amirifar; Seyyed Rashad Rouholamini; Pouria Mikaniki; Mohammad Ghorbi; Majid Kamranifar
Volume 15, Issue 4 , December 2022, , Pages 19-29
Abstract
The effects of injector pressure drop on the performance of a catalytic reactor are studied experimentally. The injectors were simple orifices. Dynamic interactions between the injector and the reactor determine the transient behavior of the system. Results showed that the injector pressure drop affected ...
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The effects of injector pressure drop on the performance of a catalytic reactor are studied experimentally. The injectors were simple orifices. Dynamic interactions between the injector and the reactor determine the transient behavior of the system. Results showed that the injector pressure drop affected neither the decomposition reaction efficiency nor the ignition delay time. However, pressure response time increased, and pressure roughness decreased with increasing injector pressure drop. Interestingly, the response time curve had a slope change at a 20% pressure drop. As discussed in the paper, the slope change is a result of cavitation phenomena in high pressure drop. It is concluded that cold injector tests are not enough for injector design validation, and performance tests are necessary tasks.
Space subsystems design: (navigation, control, structure and…)
Seyyed Rashad Rouholamini; Mohammad Ali Amirifar; Alireza Rajabi; Nooredin Ghadiri Massoom
Volume 15, Issue 3 , September 2022, , Pages 33-47
Abstract
In this paper, by creating and developing a code based on thermodynamics and gas dynamics equations, the performance characteristics of a 1N hydrazine monopropellant thruster such as thrust force, specific impulse, characteristic exhaust velocity, and propellant mass flow rate have been studied theoretically ...
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In this paper, by creating and developing a code based on thermodynamics and gas dynamics equations, the performance characteristics of a 1N hydrazine monopropellant thruster such as thrust force, specific impulse, characteristic exhaust velocity, and propellant mass flow rate have been studied theoretically in terms of reaction chamber temperature. In this regard, by taking into account the adiabatic assumption, the reaction chamber temperature of monopropellant thruster has been analyzed zero-dimensionally using the ammonia dissociation rate as an independent variable under equilibrium and non-equilibrium conditions and it has been analyzed one-dimensionally using the hydrazine and ammonia homogeneous and heterogeneous reaction rate constants. Also, the effect of nozzle throat thermal expansion on reaction chamber pressure, thrust force, and propellant mass flow rate and the effect of reaction chamber pressure on ammonia dissociation rate and consequently on reaction chamber adiabatic temperature under thermodynamic equilibrium conditions have been studied.
