Space systems design (spacecraft, satellites, space stations and their equipment)
Hossein Mahdavy-Moghaddam; Vahid Rahimi Goradel
Articles in Press, Corrected Proof, Available Online from 21 March 2023
Abstract
Each missile has a payload section and an engine section. In the path of the missile, there is a time when the mission of the engine section is over and after that the engine will not play an effective role and will be as extra weight and consequently reduced range or factor for easy detection of the ...
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Each missile has a payload section and an engine section. In the path of the missile, there is a time when the mission of the engine section is over and after that the engine will not play an effective role and will be as extra weight and consequently reduced range or factor for easy detection of the warhead by enemy agents. In such a situation, after completing the engine mission, the mechanism of separating the steps and separating the head from the body is used. One of the separation methods is to use the thrust termination system method. In this paper, with the studies performed on the thrust termination system and the presentation of mathematical relations, the pressure drop and inverse thrust created in the chamber after opening the reverse thrust valves are predicted. Also, cold type separation and thrust termination system were used and the combustion chamber pressure drop is simulated. Then, the effect of important and influential factors on the thrust termination system has been investigated.
Space systems design (spacecraft, satellites, space stations and their equipment)
Hamed Alisadesghi; Azade Khadivi; Ehsan Zabihian
Volume 15, Issue 2 , June 2022, , Pages 43-59
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 systems design (spacecraft, satellites, space stations and their equipment)
Hamed Moeini; Ebrahim Afshari; Karim Mazaheri
Volume 15, English Special Issue , May 2022, , Pages 1-13
Abstract
In the present study, the effects of geometrical properties of gas flow channels on both current density and temperature distributions inside a polymer electrolyte membrane (PEM) fuel cell are investigated. The main purpose here is to clarify the effects of the variation of width, depth, and the ribs ...
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In the present study, the effects of geometrical properties of gas flow channels on both current density and temperature distributions inside a polymer electrolyte membrane (PEM) fuel cell are investigated. The main purpose here is to clarify the effects of the variation of width, depth, and the ribs of flow channels on the fuel cell performance. To do this, the fuel cell is numerically simulated in two dimensions. The governing equations consist of the conservation of the electrical potential, Darcy’s law as alternative to the momentum equation, Maxwell-Stefan equation for mass transport, energy conservation, and electro-thermal equations along with the Butler–Volmer equation. Numerical results indicate that the width of channels and their ribs have more sensible effects than the depth of flow channels on the current density and temperature distributions and fuel cell performance. While the maximum temperature of the cell is increased by increasing the width of the flow channels, the current density distribution and fuel cell performance can be improved. By decreasing the width of their ribs or depth of channels, the performance of the fuel cell is improved and its maximum temperature is decreased.
Space systems design (spacecraft, satellites, space stations and their equipment)
Ramin Kamali Moghadam; Mohamad Taeibi; Salar Heyat Davoudian; Reinhard Miller
Volume 15, English Special Issue , May 2022, , Pages 25-33
Abstract
Superhydrophobic coatings can be made by creating a micro-sized structure on a surface providing super-repellent properties which has many applications in aerospace, defense, automotive, biomedical and engineering. Numerical simulation of drop dynamics and motion on a superhydrophobic surface helps us ...
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Superhydrophobic coatings can be made by creating a micro-sized structure on a surface providing super-repellent properties which has many applications in aerospace, defense, automotive, biomedical and engineering. Numerical simulation of drop dynamics and motion on a superhydrophobic surface helps us understand control and building surface textures and find optimum micro structured coatings of maximum hydrophobicity. In the present work, the dynamics of drops on superhydrophobic inclined micro-structured surfaces is studied, using a finite element method. Effect of microstructures on droplet behavior on a superhydrophobic surface is investigated using different microstructures. The governing equations and important dimensionless numbers are described and a numerical algorithm is introduced. The validation of the numerical algorithm is performed by simulation of drop motion attached to an inclined surface. In addition, droplet movement on the micro structured surface is numerically simulated on smooth and microstructure surfaces in the same conditions. Comparison of the results shows the effect of microstructure coating on the surface hydrophobicity properties.
Space systems design (spacecraft, satellites, space stations and their equipment)
Mostafa Jafarpanah; Hassan Naseh
Volume 14, Issue 4 , January 2022, , Pages 25-33
Abstract
The purpose of this paper is to present the cost estimation model for Cryogenic/Semi-Crogenic space propulsion systems. Therefore, the space propulsion system selection from fuel and oxidizer type aspect and achieving the maximum performance and minimum cost has been performed. Then, the fuel and oxidizer ...
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The purpose of this paper is to present the cost estimation model for Cryogenic/Semi-Crogenic space propulsion systems. Therefore, the space propulsion system selection from fuel and oxidizer type aspect and achieving the maximum performance and minimum cost has been performed. Then, the fuel and oxidizer pair samples based on the mass – energy specifications (engine weight- specific impulse) and engine operation cycle type with respect to the mission possibility has been determined. To this end, the algorithm for implementing and using the proposed cost estimation model has been designed. In this algorithm, the proposed cost estimation model is developed based on the existing cost estimation relationship and verified by comparing the existing models. Finally, the outputs in the algorithm are cost-performance (specific impulse) graph for the seven fuels and oxidizer pairwise, engine selection based on achieving maximum specific impulse and providing the design space searches for the cost and time optimization in the space projects.
Space systems design (spacecraft, satellites, space stations and their equipment)
Hanieh Eshaghnia; MEHRAN NOSRATOLLAHI; Amirhossain Adami
Volume 14, Issue 4 , January 2022, , Pages 35-49
Abstract
A new approach to the design and development of launchers is the use of advanced technologies to reduce design and development costs as much as possible. In this paper, an approach to reduce costs and increase reliability is proposed, which is based on the use of a non-turbo pump propulsion system (pressure-fed ...
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A new approach to the design and development of launchers is the use of advanced technologies to reduce design and development costs as much as possible. In this paper, an approach to reduce costs and increase reliability is proposed, which is based on the use of a non-turbo pump propulsion system (pressure-fed propulsion system) instead of a turbo pump propulsion system. For this purpose, the multidisciplinary conceptual design optimization of a two-stage launch vehicle with a pressure-fed propulsion system with the aim of sending max payload with a least gross mass to the orbit (500 km) in terms of structure, aerodynamics, propulsion, pressure vessels, simulation, and pitch program disciplines. Then, the sensitivity analysis was performed on the optimum launcher to determine the efficiency of the launcher at different orbital heights and the ability to carry a suitable payload.
Space systems design (spacecraft, satellites, space stations and their equipment)
Hojat Taei; Amirhossain Adami; Mansour Hozuri
Volume 14, Issue 4 , January 2022, , Pages 85-98
Abstract
The need to improve the reliability and safety requirements, has led to increasingly utilization of reliability based design approaches. In this study, reliability based multidisciplinary design optimization for a bipropellant propulsion system has been investigated. The objective function is minimizing ...
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The need to improve the reliability and safety requirements, has led to increasingly utilization of reliability based design approaches. In this study, reliability based multidisciplinary design optimization for a bipropellant propulsion system has been investigated. The objective function is minimizing the total system mass and design constraints are the total impulse and the temperature of the wall of the combustion chamber. Monte Carlo simulation methodology is used to apply uncertainties in the problem and to show the reliability of the system under these uncertainties. The mass, functional and geometric results of the bipropellant propulsion system are differentiated for optimal design, reliability based design and optimal reliability based design. Then, considering the results, the concepts and definitions of design methods are compared and discussed and it is shown that the reliability based multidisciplinary optimization while having the desired mass, has high reliability.
Space systems design (spacecraft, satellites, space stations and their equipment)
Alireza Mohammadi; Fathollah Ommi
Volume 13, Issue 4 , January 2021, , Pages 15-23
Abstract
This paper presents numerical study on spray characteristics and droplet distribution by using Lagrangian method in the discrete phase model of CFD. A two-fluid Eulerian method and Lagrangian approach is selected for modeling two phases turbulence flow in mixing chamber and atomization at outlet of nozzle ...
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This paper presents numerical study on spray characteristics and droplet distribution by using Lagrangian method in the discrete phase model of CFD. A two-fluid Eulerian method and Lagrangian approach is selected for modeling two phases turbulence flow in mixing chamber and atomization at outlet of nozzle while turbulence has been modeled by K-ɛ. In this study, water has been used instead of fuel and Nitrogen instead of atomization gas or oxidizer, while their ratio has been considered 0.32 to provide 26 degrees cone angle and this way, droplet‘s characteristic has been studied and compared with maximum entropy methods. Then droplet‘s diameter has been investigated by changing liquid and gas phase flow rateand based on that, we can optimize atomizer ‘s working condition with maximum efficiency with respect to its cone angle, droplet ‘s diameter and velocity and level of penetration by minimum need of experimental tests.
Space systems design (spacecraft, satellites, space stations and their equipment)
Mehran Nosratollahi; Mohammad Fatehi; Amirhossain Adami
Volume 13, Issue 3 , October 2020, , Pages 1-16
Abstract
Orbital transfer blocks has the task of transferring satellites to objective orbits from parking orbit. In this paper, Attention will be given to multidisciplinary optimal design of the propulsion system of two liquid component which is one of the most important subsystems of Orbital transfer blocks. ...
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Orbital transfer blocks has the task of transferring satellites to objective orbits from parking orbit. In this paper, Attention will be given to multidisciplinary optimal design of the propulsion system of two liquid component which is one of the most important subsystems of Orbital transfer blocks. Designing with multi objective bipropellant system, based on minimum total mass and maximum Isp, and at the end mentioned to costs and compared. For combinations of NTO as Oxidizer and fuels which are: UDMH, MMH, Hydrazine and RP-1 then for usual structures that utilized in this systems, design and optimization occurred by multi objective hybrid Particle Swarm Optimization (PSO) algorithms.
Space systems design (spacecraft, satellites, space stations and their equipment)
Maryam Kiani; Ghasem Heydari; S. Hossein Pourtakdost; Mohammad Sayanjali
Volume 13, Issue 3 , October 2020, , Pages 25-38
Abstract
Halo orbits are of importance for observation and study of the space due to their specific characteristics including the orbital position and the periodic motion. In this regards, present paper has focused on optimal trajectory planning to transfer to halo orbits. To this aim, homotopy approach has been ...
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Halo orbits are of importance for observation and study of the space due to their specific characteristics including the orbital position and the periodic motion. In this regards, present paper has focused on optimal trajectory planning to transfer to halo orbits. To this aim, homotopy approach has been adopted for optimal trajectory design. This approach has improved the convergence rate and insensitivity of the problem to initial guess. The designed trajectory transfers a spacecraft orbiting the Earth to a Halo orbit around Lagrangian point L1 of the Earth-moon restricted three-body system. The propulsion system has been assumed to be low thrust with constant specific impulse. Homotopy approach has a broad domain of applicability and methods in which continuation method has been employed here among them. The optimal designed trajectory minimizes the fuel consumption via transforming solution of the minimum energy problem utilizing the homotopy approach. This approach simplifies solution of the complex problem of minimum fuel indeed.
Space systems design (spacecraft, satellites, space stations and their equipment)
mohammad razmjooei; mohammad shahbazi; Fathollah Ommi
Volume 13, Issue 2 , May 2020, , Pages 13-35
Abstract
In this paper, the heat transfer and ablation thermal insulators in solid rocket motor are investigated. Therefore, by collecting and solving the thermal ablation equations, a computer program, using MATLAB software, is developed which can predict the thermal response of insulators in different operating ...
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In this paper, the heat transfer and ablation thermal insulators in solid rocket motor are investigated. Therefore, by collecting and solving the thermal ablation equations, a computer program, using MATLAB software, is developed which can predict the thermal response of insulators in different operating conditions and compare the performance of these insulators. The heat and mass transfer equations are considered in two dimensions in a solid body. We used the equations, finite volume method with implicit formulation for time dependency to solve equations. The reaction equation which written in the form of Arrhenius, is solved using Runge-Kutta method, and the density and the flux of the gas produced at each step are obtained. Also we represent a model for the rate of recession.
Space systems design (spacecraft, satellites, space stations and their equipment)
Hojat Taei; Pourya Shokrolahi
Volume 13, Issue 2 , May 2020, , Pages 87-96
Abstract
The final phase of orbital rendezvous and docking has been studied in this article. The main objective is to control the position of a chaser that can reach the target in the minimum time, or in other words, bypassing the optimal path. Another important objective of this paper is the minimum energy consumption. ...
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The final phase of orbital rendezvous and docking has been studied in this article. The main objective is to control the position of a chaser that can reach the target in the minimum time, or in other words, bypassing the optimal path. Another important objective of this paper is the minimum energy consumption. In the dynamic simulation, the equations of the linear form of Clohessy-Wiltshire (CWH) equations have been utilized. In linear CWH equations, the change in either direction of X or Y will result in the change in another direction and will affect the orbital docking operation. In order to achieve the objectives of this paper, the design variables should be optimized; To optimize the design variables, two methods, i.e. genetic algorithm (GA) and particle swarm optimization (PSO), have been used. Finally, to evaluate the real conditions, the results will be investigated by applying uncertainty in the outputs of thrusters.
