Space systems design (spacecraft, satellites, space stations and their equipment)
Hamed Alisadeghi; Azade Khadivi; Ehsan Zabihian
Volume 15, Issue 2 , June 2022, , Pages 43-58
Abstract
The interaction of thruster plumes with satellite components can have undesirable effects, such as disturbance force/torque, thermal loading, and species deposition in the surfaces. The purpose of this paper is to use the Direct Simulation Monte Carlo (DSMC) method to analyze the 3D plume impingement ...
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The interaction of thruster plumes with satellite components can have undesirable effects, such as disturbance force/torque, thermal loading, and species deposition in the surfaces. The purpose of this paper is to use the Direct Simulation Monte Carlo (DSMC) method to analyze the 3D plume impingement flows and investigate its effects. Two impingement problems are computed. The impact of a jet of nitrogen on an inclined flat plate is considered. Good agreement is found between surface quantities calculated by DSMC and experimental data. The plume of a hydrazine control thruster firing in a model satellite configuration is simulated. Surface quantities and net impingement effects are calculated. The effects of partial displacement of the thruster locations on the results have also been investigated. The results show that a 20% displacement of the thruster location can change the disturbance force/torque by up to 15% of the initial values.
Space subsystems design: (navigation, control, structure and…)
Ehsan Maani; Peyman Nikpey; Ehsan Zabihian
Volume 14, Issue 1 , March 2021, , Pages 23-33
Abstract
n GEO communicational satellites, thrusts are being used for many missions such as station keeping, longitude change maneuver and actuators desaturation. These types of actuators need fuel and its estimation requires many complicated calculations. In this paper, a novel method based on availed data for ...
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n GEO communicational satellites, thrusts are being used for many missions such as station keeping, longitude change maneuver and actuators desaturation. These types of actuators need fuel and its estimation requires many complicated calculations. In this paper, a novel method based on availed data for previous satellites is proposed for estimation of satellite fuel mass and it does not need mathematical modeling of satellite dynamics. Two methods, least square method and artificial intelligence, are used to this aim and two mathematical model are proposed for satellite fuel mass estimation. By applying the models to several previous satellites, it is shown that the models have lower than 5% average error. The proposed method in this paper is quick and accurate and can be utilized for GEO satellites feasibility study and conceptual design
Zeynab Aghajani; Ehsan Zabihian; Mehran Mirshams
Volume 10, Issue 4 , March 2018, , Pages 41-54
Abstract
The significance and the wide use of geostationary communication satellites and the long hours of work in the process of their conceptual design was the main motivation to develop a software based on the statistical design to reduce the time spent on the conceptual design phase. This software is based ...
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The significance and the wide use of geostationary communication satellites and the long hours of work in the process of their conceptual design was the main motivation to develop a software based on the statistical design to reduce the time spent on the conceptual design phase. This software is based on the statistical and parametric design method. The statistical model used in this software includes a database of 147 satellites launched between 2010 and 2016. To increase the accuracy of the software, the combined parametric model has been used from selected design references. The software is based on MATLAB and to make it more user friendly, the graphical GUI was used. In this article, the design of the software is presented and there is focus on the design and verification method. The accuracy of this tool was amply verified through a flight prototype, indicating the average error of 16% in the obtained results.
Mehran Mirshams; Ehsan Zabihian
Volume 10, Issue 3 , December 2017, , Pages 1-14
Abstract
This study introduces a new computer code termed AZMIN developed by Space Research Laboratory (SRL). This efficient tool which benefits from the Statistical Design Model (SDM) has been developed for the system design of GEO communication satellites. The main advantage of the AZMIN is to determine technical ...
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This study introduces a new computer code termed AZMIN developed by Space Research Laboratory (SRL). This efficient tool which benefits from the Statistical Design Model (SDM) has been developed for the system design of GEO communication satellites. The main advantage of the AZMIN is to determine technical specification parameters of a satellite at both system and subsystem levels, with a high accuracy and time performance. System-level parameters encompass mass, power, dimension and cost; while, subsystem parameters contain mass, power, and solutions for components configurations of each subsystem. Actual computations of this tool are carried out by means of SDM, leading to a dramatic decrease in the conceptual design time and consequently, its cost. The database utilized is composed of records of 462 GEO communication satellites launched from the year 2000 to 2017. The accuracy of the AZMIN code is amply verified through an example and also a statistical method, demonstrating the mean error of approximately 15% in the obtained results.
Mehrn Mirshams; Asad Saghari; Ehsan Zabihian
Volume 8, Issue 3 , October 2015, , Pages 55-63
Abstract
This paper proposes a supplementary method for conceptual design of satellite electrical power subsystem(EPS). Each of represented methods for satellite electricalpower subsystemconceptual design in different references have some advantages and also disadvantages, besides in each of the methods a determined ...
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This paper proposes a supplementary method for conceptual design of satellite electrical power subsystem(EPS). Each of represented methods for satellite electricalpower subsystemconceptual design in different references have some advantages and also disadvantages, besides in each of the methods a determined part of this subsystem has been in focused. In this research, first advantages and disadvantages of existing approaches for the conceptual design of electrical power subsystemwere reviewed, continued with combining of previous methods, improved relationships and using some of the simulation methods plus the using of statistical databases, a complementary method with more ascendency and less disadvantages in comparison with other approaches was presented. Finally, using a data from a specific satellite and the results of the statistical design, the complementary method has been validated.
