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 systems design (spacecraft, satellites, space stations and their equipment)
Sajjad Davari; Hadiseh Karimaei; Mohammad Reza Salimi; Hassan Naseh
Volume 16, Issue 1 , April 2023, , Pages 35-46
Abstract
Monopropellant thruster are used to inject a satellite into orbit or control its position on three axes in space missions. One of them is hydrazine thruster which is widely used. In this research, design of the injector, decomposition chamber and nozzle of a 10N hydrazine monopropellant thruster have ...
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Monopropellant thruster are used to inject a satellite into orbit or control its position on three axes in space missions. One of them is hydrazine thruster which is widely used. In this research, design of the injector, decomposition chamber and nozzle of a 10N hydrazine monopropellant thruster have been performed. The capillary injector was designed using Fluent software for this thruster which was able to supply the mass flow rate of the thruster (5 gr/sec). The decomposition chamber contains catalyst granules and its dimensions were selected based on the complete decomposition of hydrazine. The nozzle was designed by RPA software. The validation of the design with RPA software was checked by a numeric code. This code was able to calculate the dimensions of the decomposition chamber based on the amount of hydrazine decomposition. Accordingly, the results of both design methods are strongly consistent with each other. At the end of the design, the final thruster design and drawings were prepared.
Space systems design (spacecraft, satellites, space stations and their equipment)
Sajad Davari; Hadiseh Karimaei
Volume 15, Issue 3 , September 2022, , Pages 115-125
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.
Hadiseh Karimaei
Volume 12, Issue 2 , September 2019, , Pages 11-21
Abstract
the effect of the internal geometry of the injector of a low-thrust monopropellant thruster on the characteristics of the outlet liquid sheet, such as the liquid sheet thickness, the spray cone angle, the average output velocity, and its mass flow rate, have been studied. For this purpose, simulation ...
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the effect of the internal geometry of the injector of a low-thrust monopropellant thruster on the characteristics of the outlet liquid sheet, such as the liquid sheet thickness, the spray cone angle, the average output velocity, and its mass flow rate, have been studied. For this purpose, simulation of the internal flow based on the computational fluid dynamics was performed to predict the output flow characteristics, then parametric studies were conducted to investigate the effect of geometry. In order to extract a predictive model for the preliminary design of the injector, a neural fuzzy network model was used. Using this model, the results of parametric analyzes were used to obtain a geometric specification without geometric modeling and computational fluid dynamics analysis or the use of initial design methods. The purpose of the implementation of the neural network model is to obtain an estimate of the internal geometry of the injector by entering the desired macroscopic characteristics of the output flow.
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.
Hadiseh Karimaei; Ramin Ghorbani; Seyed Mostafa Hoseeinalipour
Volume 11, Issue 4 , March 2019, , Pages 1-10
Abstract
In the atomization process, small disturbances grow in liquid jet or sheet and eventually cause to disintegrate it into ligaments and smaller droplets. Concerning to the motion of waves on the liquid sheet surface, the stage of primary breakup is deterministic and can be predicted by instability analyzes. ...
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In the atomization process, small disturbances grow in liquid jet or sheet and eventually cause to disintegrate it into ligaments and smaller droplets. Concerning to the motion of waves on the liquid sheet surface, the stage of primary breakup is deterministic and can be predicted by instability analyzes. In early studies, the theories of linear and weakly nonlinear instability have been implemented on a cylindrical liquid sheet and the effect of spray cone angle was not included in the model. Therefore, in this paper in order to improve the model, the linear instability theory is implemented on a cone-shaped liquid sheet for the first time, and therefore radial velocities of liquid and gas phases are also considered moreover than axial and tangential velocities. The results of this improved model such as maximum wave growth rate and its corresponding wave number can be used to estimate mean droplet diameter and breakup length.
Hadiseh Karimaei
Volume 11, Issue 3 , December 2018, , Pages 9-19
Abstract
Monopropellant thruster of atitude control system is a requirement for the development and functionalization of satellites in space, which have expensive and high-tech technology. Hydrazine thrusters are currently the most widely used thrusters for guidance and control systems of re-entry and manned ...
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Monopropellant thruster of atitude control system is a requirement for the development and functionalization of satellites in space, which have expensive and high-tech technology. Hydrazine thrusters are currently the most widely used thrusters for guidance and control systems of re-entry and manned spacecraft. In this paper, design and computation of an injector with hollow-cone spray with two tangential inlets as a fuel injector of a 10N monopropellant hydrazine thruster is presented. This injector has designed based on Bazarov method so that can generate a spray with a common (not so big) spray angle and very thin liquid sheet. Therefore it will be suitable from aspect of limitation of the catalyst bed length and also gives finer atomization.The phenomenon of creating and developing an air core in the internal flow of these injectors and its simulation is complex due to the existence of two turbulent swirl flows in two different phases, liquid and gas, which have an interface. For this injector, simulation of the internal flow has been performed to predict the output flow characteristics and ensure the formation of the gas core inside it. These characteristics include the spray cone angle, liquid sheet thickness, the output velocity distribution of the injector nozzle, and etc. For this purpose, volume of fluid (VOF) method has been used and flow turbulence has been simulated using the k-emodel. The results of this study is presented in detail in the paper.
Hadiseh Karimaei; Mostafa Hossein Alipour; F Ommi; Ehsan Movahednejad; Reza Sharifzadeh
Volume 10, Issue 4 , March 2018, , Pages 1-7
Abstract
A swirl injector is tested to investigate the instability of the liquid sheet emanating from it and determine the main microscopic characteristics of the spray. The injector, which is tested, was already approved by doing the characterization tests (macroscopic). Due to the fact that the PDPA systems ...
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A swirl injector is tested to investigate the instability of the liquid sheet emanating from it and determine the main microscopic characteristics of the spray. The injector, which is tested, was already approved by doing the characterization tests (macroscopic). Due to the fact that the PDPA systems to measure the spray characteristics are very expensive and high-tech, and therefore inaccessible for us , it is attempted to investigate the specifications and instability of the liquid sheet as much as possible, by photography. The liquid sheet emanating from the injector has perturbations on its surface which originate from inside the injector. Due to the aerodynamic interactions, these perturbations grow and eventually lead to break up the liquid sheet and form the ligaments. The growth of these unstable waves can be observed in the images. Also the breakup length can be measured using the images recorded. Also ligaments in the primary breakup zone and droplets were shown.
Hadiseh Karimaei; seyed mostafa hosseinalipour
Volume 10, Issue 3 , December 2017, , Pages 59-65
Abstract
The droplet formation stage of a spray, which enjoys a great diversity in size and droplet velocity, is predictable through a statistical approach. Since the available methods require experimental data such as mean droplet diameter and mean droplet velocity as inputs to estimate the distribution of the ...
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The droplet formation stage of a spray, which enjoys a great diversity in size and droplet velocity, is predictable through a statistical approach. Since the available methods require experimental data such as mean droplet diameter and mean droplet velocity as inputs to estimate the distribution of the droplets, this study attempts to propose a consistent theoretical model based on the energy conservation equation for the estimation of mean droplet diameter to be used in the predictive models of droplet size distribution, such as maximum entropy model. Therefore, those models can be independent of experimental data. The parameters needed in the model, such as atomization efficiency and the Weber number are provided using a CFD model. Then, a parametric study to evaluate the relationship between the atomization efficiency and spray velocity, and mean droplet diameter is carried out. This new proposed model entitled energy-based model (EBM) can provide a very good prediction of mean droplet diameter in comparison with the available experimental data.
