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Structural Design of a Launch Vehicle with Reusable First Stage
, M.Sc. Thesis Sharif University of Technology ; Haddadpour, Hassan (Supervisor)
Abstract
Aerodynamics loads and aeroheating during reentry, are one of the challenging issues in designing One of the main challenges in the design and application of reusable spacecrafts is the aerodynamic and thermal loads acting on their structures during reentry into the atmosphere. For this reason, all the concepts/prototypes presented in the 20th century were either not fully reusable, or were partially canceled, or did not have economic justification. In this report, the aerodynamic loads on the first stage of a launch vehicle during the launch and return phases have been investigated. Due to the fact that the main part of the first stage of the vehicle includes fuel and oxidizer tanks, the...
Dynamic modeling and structural reliability of an aeroelastic launch vehicle
, Article Advances in Aircraft and Spacecraft Science ; Volume 9, Issue 3 , 2022 , Pages 263-M278 ; 2287528X (ISSN) ; Khodabaksh, A. H ; Sharif University of Technology
Techno-Press
2022
Abstract
The time-varying structural reliability of an aeroelastic launch vehicle subjected to stochastic parameters is investigated. The launch vehicle structure is under the combined action of several stochastic loads that include aerodynamics, thrust as well as internal combustion pressure. The launch vehicle's main body structural flexibility is modeled via the normal mode shapes of a free-free Euler beam, where the aerodynamic loadings on the vehicle are due to force on each incremental section of the vehicle. The rigid and elastic coupled nonlinear equations of motion are derived following the Lagrangian approach that results in a complete aeroelastic simulation for the prediction of the...
Decision Matrix for Time-Critical Optimal Trajectories for Air-Launch of Small Satellites
, M.Sc. Thesis Sharif University of Technology ; Malaek, Mohammad Bagher (Supervisor)
Abstract
One of the satellite time-critical launch methods is air-launch, which is considered in this research thoroughly. The Large number of important parameters of this method makes the system highly complex. In such complex systems, usual methods of design and development will not be effective. Moreover, based on systemic approaches, interfaces between different elements of a complex system have significant effects on the performance of the whole system. One of the methods for analysis of such systems is “Design Structure Matrix” or DSM. This method is based on system engineering principles and has confirmed capabilities in analysis of highly coupled systems.
In this research, the air launch...
In this research, the air launch...
Decision Matrix for a Safe Aerial Launch Release Mechanism
, M.Sc. Thesis Sharif University of Technology ; Malaek, Mohammad Bagher (Supervisor)
Abstract
The case of rapid small satellite aerial launch by mother airplane has various applications; such as space experiment, weather monitoring, and getting information from the earth monitoring during natural disasters. In this method, the satellite and the launch vehicle will be carried up by mother airplane to the definite height; then, the launch vehicle will be released and flied - to the insert of satellite into the desired orbit. Aerial launch system success depends on a set of complex elements and their interactions. In the present study, first of all, the element interactions will be investigated by system engineering approach based on operational scenarios; then, a new approach for...
Finite element modeling of incremental bridge launching and study on behavior of the bridge during construction stages
, Article International Journal of Civil Engineering ; Volume 13, Issue 1 , 2015 , Pages 112-125 ; 17350522 (ISSN) ; Tajmir Riahi, H ; Hirmand, M ; Sharif University of Technology
Iran University of Science and Technology
2015
Abstract
Incremental launching is a widespread bridge erection technique which may offer many advantages for bridge designers. Since internal forces of deck vary perpetually during construction stages, simulation and modeling of the bridge behavior, for each step of launching, are tedious and time consuming tasks. The problem becomes much more complicated in construction progression. Considering other load cases such as support settlements or temperature effects makes the problem more intricate. Therefore, modeling of construction stages entails a reliable, simple, economical and fast algorithmic solution. In this paper, a new Finite Element (FE) model for study on static behavior of bridges during...
Modeling and direction control of a 2 D.O.F. Heavy launching bed on a moving car using a full suspension model
, Article 2003 ASME Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Chicago, IL, 2 September 2003 through 6 September 2003 ; Volume 5 B , 2003 , Pages 1677-1685 ; Afsharzadeh, A ; ASME ; Sharif University of Technology
American Society of Mechanical Engineers
2003
Abstract
In this paper dynamic modeling and direction control of a launching bed (L.B.) with 2 D.O.F. rotation around vertical and lateral axes, mounted on a vehicle moving on a rough road is investigated. The purpose of direction control is to bring the L.B. from any initial angle to a desired angle with respect to the reference frame and to keep it there. The vehicle model is a full car with bounce, yaw, roll and pitch degrees of freedom. The suspension system of the vehicle is considered to have passive elements and unsprung masses. The stiffness of the tires is also included in the model. To control the position of the launching bed, a servo-hydraulic system comprising of hydro-motors, gearboxes,...
A Study of New Product Launching and Marketing Planning; (a Case of Introducing Liquid Waterproofing Systems into the Iranian Construction Market)
, M.Sc. Thesis Sharif University of Technology ; Beirjandi, Heshmat (Supervisor)
Abstract
As a strategically critical stage of new product development, launch process has attracted a lot of attention. A lot of study has been done about launch and its effect on product performance.The objective of this thesis is to gain more understanding about new product launch and the way it is executed. The aim is to create a process description of product launch; how the process begins and how different phases follow each other until the introduction of new product. The main research problem is how new product launch can be described as a marketing-focused process. Further, the research problem is answered through literature review and empirical case study research. The literature review...
Integrated Robust Guidance and Control of VTVL Reusable Launch Vehicle at Terminal Phase Using Sliding Mode Control
, M.Sc. Thesis Sharif University of Technology ; Fathi Jegarkandi, Mohsen (Supervisor)
Abstract
In this article, guidance and control of reusable launch vehicle at terminal phase has been studied. The goal of this article is increasing the accuracy and safety of the guidance and control system of the launch vehicle in order to successfully land on ground surface. Integrated guidance and control, being a novel method in guidance and control, is used to guide the launch vehicle in the re-entry phase and landing phase on ground surface. The returning object studied is a Falcon 9 rocket for which we find the 6 DOF model. The landing method of this vehicle is vertical. Implementing an integrated guidance and control system is a novel approach in this area. The controller used in this...
Multidisciplinary Design Optimization of an Air Launch Satellite Launch Vehicle by Considering the Coupled Slosh–vehicle Dynamics
, M.Sc. Thesis Sharif University of Technology ; Fathi, Mohsen (Supervisor)
Abstract
In this thesis, the multidisciplinary design of liquid propellant satellite launch vehicle has been done by taking into consideration the effects of fuel sloshing. At first, the theory of multidisciplinary design and one-level architecture with the label of multidisciplinary feasibility have been used. In the following, Gravitational Search Algorithm (GSA) and Particle swarm optimization (PSO) have been developed. Then, the multidisciplinary design cycle began with the design of the liquid propellant system. In the propulsion section, the selection of the optimal fuel, the design of the nozzle, motor and the selection of the optimal engine cycle considering the geometric and mass...
Launch Abort System Design for Manned Launch Vehicle
, M.Sc. Thesis Sharif University of Technology ; Fathi, Mohsen (Supervisor)
Abstract
In sending a man into space, the protection of the lives of the astronauts is very important and must ensure them stay healthy. To launch a human into space must design a system that if creates a problem can protect the lives of astronauts. To achieve this goal requires the design of a system for launch vehicle that be named launch cancellation system (emergency escape system). In this project, the launch escape system for manned lauch vehicle is designed. The cargo carrier serves as input for the problem and then the system is designed to build in our country. First, to study emergency escape systems in the world were discussed and sub-systems and scenario of flight was specified for...
An accurate guidance algorithm for implementation onboard satellite launch vehicles
, Article Scientia Iranica ; Volume 17, Issue 2 D , JULY-DECEMBE , 2010 , Pages 175-188 ; 10263098 (ISSN) ; Mobed, M ; Sharif University of Technology
2010
Abstract
An algorithm for guiding a launch vehicle carrying a small satellite to a sun synchronous LEO is presented. Before the launch, a nominal path and the corresponding nominal control law for the entire journey are computed. For each sampling instant during the guided flight, a linear equation approximately relating the differences between the actual and nominal values is considered, and a LeastSquares formula using data from on-line state measurements is applied to compute the actual control. The coefficient matrices of the Least-Squares formula can be determined by off-line computations. The method enjoys simplicity of implementation by onboard computers, as well as robust accuracy against...
rajectory Optimization of the Internally Carried Air Launch
, M.Sc. Thesis Sharif University of Technology ; Asadian, Nima (Supervisor) ; Fathi, Mohsen (Supervisor)
Abstract
One of the most interesting and at the same time the newest methods to launch a satellite into space is Air Launch or Launch throw the mother aircraft. The placement of the satellite into space by a rocket in specific altitude and speed is separated from the mother aircraft, takes place. The most problems in multi stage rocket launching is trajectory optimization to reaching the maximum height. The survey was conducted using classical optimization methods, which is derived the equations for the gradient based on the calculus of variations. that can be used or modified for emissions control wings and changing the direction of thrust exhaust. It should be noted that in the model of rigid body...
A Low Altitude Optimal-fuzzy Guidance Algorithm for a Vertically Launched Flying Vehicle
, M.Sc. Thesis Sharif University of Technology ; Nobahari, Hadi (Supervisor) ; Kashefi, Saeed (Co-Advisor)
Abstract
An optimal-fuzzy low altitude two phase CLOS guidance algorithm for a vertically launched flying vehicle is presented. In addition, the required relations for determining the proper rotation angle of interceptor in the launch phase are derived. The guidance algorithm is designed for a three point guidance system and utilizes fuzzy sliding mode control as a regulator to compensate the guidance loop errors. Furthermore, for the purpose of trajectory shaping, a fuzzy system was employed to calculate the augmented elevation angle. Finally, a multi-objective optimization algorithm is used to determine 20 unknown parameters of the guidance law and 11 parameters of trajectory shaping system....
Development of an Active Guidance Method For Satellite Carrier
, M.Sc. Thesis Sharif University of Technology ; Pourtakdoost, Hossein (Supervisor)
Abstract
A carrier should be used a guidance system for reaching to the point of injection in an orbit. The main purpose of guidance system in the injection process is issuance of guidance commands to achieve the final desirable velocity and position. These velocity and position indicate the purpose orbit for injection. Carrier is a dynamic system which is described by mathematical terms. In general carrier guidance systems apply pitch angle or rate of pitch angle to reach specific path over injection process. Different methods are available for carrier guidance such that preset method. In this method, the guidance system addresses specific guidance commands and control system performs these...
Analysis of Launch Time in New Product Development With Risk Considerations
,
M.Sc. Thesis
Sharif University of Technology
;
Sheikhzadeh, Mehdi
(Supervisor)
Abstract
The importance of New Product Development (NPD) projects has been realized more and more in recent years. Among different decisions to be made in NPD process, one of the most critical decisions is about the best time to launch new product(s). Due to existence of many internal and external influential factors, determining the optimal launch time is often too complicated and it is quite hard to systematically analyze it. Despite risky nature of NPD, risk considerations in determining the optimal launch time have not been addressed in literature due to the mentioned complexity. In this research, we developed a model that takes in to account risk considerations while systematically determining...
Design, Simulation, and Error Analysis for Guidance Law of a Satellite Launcher
, Ph.D. Dissertation Sharif University of Technology ; Mobed, Mohammad (Supervisor) ; Mohammadi, Ali (Supervisor)
Abstract
The problem of launching a satellite to low earth orbit has been considered. Preliminary concepts such as satellite orbits, launcher missiles and their equations of motion, and traditional methods for guidance of launchers are reviewed first. Then a new method for optimizing the launch trajectory under non-ideal conditions is introduced in which the solution of a known ideal trajectory optimization problem is used as an initial guess for the actual optimization problem. Several methods for guiding a launcher to place a satellite in Earth orbit are presented next; they have been titled as (1) launch path re-computation outside the atmosphere, (2) prediction error minimization, and (3) output...
Reliability Assessment, Allocation and Optimization for Launching Systems
, Ph.D. Dissertation Sharif University of Technology ; Pourtakdoost, Hossein (Supervisor)
Abstract
The subject of systemic reliability assessment, allocation and optimization as well as structural reliability (SR) of a two stage solid fuel launch vehicle (LV) is investigated. In this regards, first the LV reliability block diagram is broken-down into appropriate subsystems. Subsequently the total LV system reliability is determined assuming the subsystems reliability. In addition, using a hybrid GA-PSO algorithm optimal subsystems redundancy levels, reliabilities as well their type are determined to simultaneously maximize the total reliability while minimizing the LV cost (weight) as a constraint. While the reliability and cost of subsystems are not precisely known, the total LV...
One cube or more?
, Article 59th International Astronautical Congress 2008, IAC 2008, Glasgow, 29 September 2008 through 3 October 2008 ; Volume 6 , 2008 , Pages 3792-3797 ; 9781615671601 (ISBN) ; Shahmari, E ; Molaverdikhani, K ; Jazebizadeh, H ; Taheran, M ; Sharif University of Technology
2008
Abstract
In the recent years, many universities invest on cubesats to prepare an appropriate environment for their students to get their hands on real experiments including design, fabrication, test, launch, operation and analysis of a real satellite project. Now after 5 years of experimentation, it is time for leaders to define more practical goals beside training students. Orienting the budget that is annually being invested on such satellites in every country to a specific goal could be a driving force in opening a new chapter in the utilization of pico-satellites and the advantages they offer. As these tiny satellites are utilized based on low cost COTS and also are light weight enough to reduce...
Reliability-Based Multidisciplinary Design Optimization Under Uncertainty for Reusable Flexible Launch Vehicle Using Genetic Algorithm
, M.Sc. Thesis Sharif University of Technology ; Fathi Jegarkandi, Mohsen (Supervisor)
Abstract
In this research, a Reusable Flexible Launch Vehicle (RFLV) design problem is presented by Multi-Disciplinary Design Optimization (MDO) approach in primary design phase. Trajectory, structure, aerodynamic, aeroelasticity and thermal protection system are considered as involved disciplines in design problem. The study purpose will be to obtain an optimal trajectory which meets all the control and structure limitation while the estimating body skin and thermal protection thicknesses base on structural evaluating in re-entry trajectory is in process. The flexible launch vehicle body is considered as a free-free Bernoulli-Euler beam and D’alembert’s principle addresses inertia force in static...
Stability analysis of elastic launch vehicles with fuel sloshing in planar flight using a BEM-FEM model
, Article Aerospace Science and Technology ; Volume 53 , 2016 , Pages 74-84 ; 12709638 (ISSN) ; Haddadpour, H ; Ebrahimian, M ; Sharif University of Technology
Elsevier Masson SAS
2016
Abstract
A numerical model is developed for investigation of coupled dynamics of fuel contained elastic launch vehicles in planar atmospheric flight. Finite element method along with the linear quasi-steady piston aerodynamic theory is used for developing an aeroelastic model. A reduced order boundary element model is used for modeling the liquid sloshing in tanks. The interaction of sloshing and aeroelasticity is studied using stability analysis of the coupled system. Results show that the slosh-aeroelastic coupling in an elastic launch vehicle occurs for low tank filling ratios and may lead to decreasing the system damping. Due to more interactions between the slosh and rigid body modes, larger...