Space systems design (spacecraft, satellites, space stations and their equipment)
Sajjad Davari; Hadiseh Karimaei; Mohammad Reza Salimi; Hassan Naseh
Volume 16, Issue 2 , June 2023, , Pages 55-61
Abstract
In this paper, the catalyst bed of a 10 N hydrazine monopropellant thruster was designed. The catalyst bed is including iridium granules, which is used to decompose the hydrazine in monopropellant thruster. Hydrazine must be decomposed almost completely in the catalytic chamber, because it is a carcinogenic ...
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In this paper, the catalyst bed of a 10 N hydrazine monopropellant thruster was designed. The catalyst bed is including iridium granules, which is used to decompose the hydrazine in monopropellant thruster. Hydrazine must be decomposed almost completely in the catalytic chamber, because it is a carcinogenic chemical fuel and on the other hand, achieving the maximum power from the thruster is also an important goal. As a result, the effect of change in catalytic chamber length on the mass fraction of chemical species including hydrazine, ammonia, nitrogen, and oxygen was studied. Also, after determining the length of the catalytic chamber, the diameter of the nozzle throat corresponding to the same length was determined.
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.
Space systems design (spacecraft, satellites, space stations and their equipment)
Sajad Davari; Hadiseh Karimaei
Volume 15, Issue 3 , September 2022, , Pages 109-118
Abstract
In this research, design and simulation of a single capillary injector and three-hole circular injector plate of a 10N Hydrazine monopropellant thruster were performed. Ansys Fluent software was used to simulate the injector and injector plate . Volume of fluid (VOF) method was used to simulate such ...
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In this research, design and simulation of a single capillary injector and three-hole circular injector plate of a 10N Hydrazine monopropellant thruster were performed. Ansys Fluent software was used to simulate the injector and injector plate . Volume of fluid (VOF) method was used to simulate such a flow and turbulence was simulated by k-e model. The characteristics of the injector and injector plate including mass flow rate and average velocity in the injector nozzle were calculated by changing the inlet pressure. The results showed that the injector and the injector plate have the ability to supply the desired mass flow rate of the monopropellant thruster at a known design pressure. In fact the capillary injector has replaced swirl injector with hollow cone spray used in the previous version of this thruster. The dimension of the chamber was significantly reduced by using the capillary injector, which reduces both the volume of the expensive iridium catalyst and weight of the thruster.
Space systems design (spacecraft, satellites, space stations and their equipment)
Mohammad Reza Salimi
Volume 15, Issue 1 , March 2022, , Pages 93-110
Abstract
In present study, a hydrazine based monopropellant thruster decomposition chamber is simulated numerically. The catalyst bed separated in two sides, the particles size in upstream side is larger than those in downstream side. Effects of upstream side length and its particles diameter on catalyst bed ...
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In present study, a hydrazine based monopropellant thruster decomposition chamber is simulated numerically. The catalyst bed separated in two sides, the particles size in upstream side is larger than those in downstream side. Effects of upstream side length and its particles diameter on catalyst bed characteristics were investigated. To this end, three standard particles sizes of mesh: 16.5, 25 and 30 for the upstream side and two standard particles diameter of 1/8 and 1/16 (in) for downstream side were analyzed. Additionally, three upstream side lengths of 2.5, 5 and 7.5 (mm) were used while the length of bed is 6.5 (cm). Simulations were performed in three bed loading coefficients of 16.5, 25 and 35 (kg/m2s). The related results showed the effectiveness of upstream side on flow and thermal fields are strongly depends on the ration of particles sizes in upstream and downstream sides. Moreover, the upstream side length and bed loading are two important factors affecting the upstream side effectiveness.
Hadiseh Karimaei; Mohammad Reza Salimi; Hassan Naseh; Ehsan Jokari
Volume 12, Issue 1 , April 2019, , Pages 13-22
Abstract
In this paper, design and physical configuration of various components of a 10N Monopropellant Hydrazine Thruster focusing on design calculations and optimization of catalytic combustion chamber. According to this design, a prototype of the thruster will be manufactured. The mentioned thruster has been ...
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In this paper, design and physical configuration of various components of a 10N Monopropellant Hydrazine Thruster focusing on design calculations and optimization of catalytic combustion chamber. According to this design, a prototype of the thruster will be manufactured. The mentioned thruster has been designed as a three-piece modular thruster, including an injection system, catalytic combustion chamber and nozzle. Based on analyzes done for each module, the propulsion characteristics of monopropellant thruster system have been identified and used for the next module as necessary inputs. The combustion chamber dimensions are selected based on criterion of maximum decomposition of 40% ammonia and Mach number of 0.02. Also, the third module is the nozzle, designed as a simple cone. The exterior body design of these three modules and their connections to each other, based on considerations of sizing and weight limitation, as well as being dual purpose for use in the cold and hot tests, has been performed.