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Master's Projects

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search.filters.applied.f.advisor: Olds, John R. × End date: 2004 × Start date: 2004 ×

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Now showing 1 - 8 of 8
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    Discrete Event Simulation of Reusable Launch Vehicle Ground Operations (RLVSim)
    (Georgia Institute of Technology, 2004-07-30) Reeves, John Daniel, Jr.
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    Development of An Online Database Tool for Quick Access to Mass Estimating Relationships
    (Georgia Institute of Technology, 2004-05-01) Pimentele, Janssen
    This document describes the methods and approach used in the development of an online database tool used for quick access to mass estimating relationships. The resulting tool is GOMER – Georgia Tech Online Mass Estimating Resource. This tool utilizes a typical three-tier database architecture employed by many web database applications. A unique relationship scheme was used to preserve the complex relationships found in the data sets. This scheme allows the user to search through the database using a variety of methods, while returning a list of results that can be examined in further detail. MySQL and PHP were used extensively throughout in the creation and implementation of the GOMER database.
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    Responsive Access Small Cargo Affordable Launch (RASCAL) Independent Performance Evaluation
    (Georgia Institute of Technology, 2004-05-01) Young, David
    RASCAL is a Defense Department initiative that stands for Responsive Access, Small Cargo, Affordable Launch [2]. The overall launch concept involves three stages. The first stage will consist of a reusable aircraft similar to a large scale Air Force fighter. The first stage will also utilize Mass Injection Pre-Compressor Cooling (MIPCC) turbojet engines that will propel the stage to approximately two hundred thousand feet before releasing the second and third rocket stages. The first stage will be similar to a large fighter of the F-22 class, although the turbofans will be that of the more available F100 class. The MIPCC system will be a plug-in addition to the engines to help high altitude performance. This stage will be not only a “Launch Platform”, but more of a first stage in that it will contribute significantly to the overall acceleration of the vehicle The second and third stages will consist of simple expendable rockets. Releasing the upper stages outside the atmosphere will reduce the loads on the stages as well as the risk of staging. Also by relying on the reusable portion for all atmospheric flight, the expendable stages can be designed simpler and therefore cheaper. The purpose of this project is to compare the published RASCAL numbers with those computed using a design methodology currently used in the Space System Design Laboratory (SSDL) at The Georgia Institute of Technology. When the initial Space Launch Corporation design was evaluated using the SSDL methodology it was found to fall short of the performance as well as the cost goals set by DARPA for the RASCAL program. The baseline vehicle was found to only carry 52 lbs to the 270 nmi sun synchronous orbit. Several alternatives were evaluated off of the baseline design. The best of these alternatives can meet DARPA’s performance goals and reach the cost goals of $5,000 per pound of payload with eight first stage vehicles flying 46 times per year for a total of 363 flights per year. Different economic cases were also evaluated to try and meet the cost goals in a less ambitious number of flights per year. It was found that if the DDT&E was paid for by another party (NASA, DOD, etc.) the cost goals can be met with just three vehicles flying 42 times per year for a total of 125 flights per year.
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    Evaluation of Multidisciplinary Optimization (MDO) Techniques Applied to a Reusable Launch Vehicle
    (Georgia Institute of Technology, 2004-04-29) Brown, Nichols
    Optimization of complex engineering systems has always been an integral part of design. Due to the size and complexity of aerospace systems the design of a whole system is broken down into multiple disciplines. Traditionally these disciplines have developed local design tools and computer codes (legacy codes) allowing them to perform optimization with respect to some aspect of their local discipline. Unfortunately, this approach can produce sub-optimal systems as the disciplines are not optimizing with respect to a consistent global objective. Multidisciplinary design optimization (MDO) techniques have been developed to allow for multidisciplinary systems to reach a global optimum. The industry accepted All-at-Once (AAO) technique has practical limitations and is confined to only small, conceptual level problems. New multi-level MDO techniques have been proposed which may allow for the global optimization of the large, complex systems involved in higher levels of design. Three of the most promising multi-level MDO techniques, Bi-Level Integrated System Synthesis (BLISS), Collaborative Optimization (CO) and Modified Collaborative Optimization (MCO) are applied, evaluated and compared in this study. The techniques were evaluated by applying them to the optimization of a next generation Reusable Launch Vehicle (RLV). The RLV model was composed of three loosely coupled disciplines, Propulsion, Performance, and Weights & Sizing, composed of stand-alone, legacy codes not originally intended for use in a collaborative environment. Results from the multi-level MDO techniques will be verified through the use of the AAO approach and their benefits measured against the traditional approach where the multiple disciplines are converged using the fixed point iteration (FPI) process. All the techniques applied will be compared against each other and rated qualitatively on such metrics as formulation and implementation difficulty, optimization deftness and convergence errors. i
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    A Case Study of the STS Indirect and Support Costs
    (Georgia Institute of Technology, 2004-04-23) Krevor, Zachary C.
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    Development of An Online Database Tool for Quick Access to Mass Estimating Relationships: GOMER - Georgia Tech Online Mass Estimation Resource Administrator/Developer's Guide
    (Georgia Institute of Technology, 2004-04-01) Pimentele, Janssen
    This document describes the methods and approach used in the development of an online database tool used for quick access to mass estimating relationships. The resulting tool is GOMER – Georgia Tech Online Mass Estimating Resource. This tool utilizes a typical three-tier database architecture employed by many web database applications. A unique relationship scheme was used to preserve the complex relationships found in the data sets. This scheme allows the user to search through the database using a variety of methods, while returning a list of results that can be examined in further detail. MySQL and PHP were used extensively throughout in the creation and implementation of the GOMER database.
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    Analytical Structural Weight Estimation of Conceptual Launch Vehicle Fuselage Components with the Georgia Tech Structural Tool for Rapid Estimation of Shell Sizes (GT-STRESS)
    (Georgia Institute of Technology, 2004-03-05) Hutchinson, Virgil L., Jr.
    Many conceptual launch vehicles are designed by the integration of various disciplines, such as aerodynamics, propulsion, trajectory, weights, and aeroheating. In the determination of the total vehicle weight, a large percentage of the vehicle weight is composed of the structural weight of the vehicle subsystems, such as propellant tanks. The weight of each subsystem is derived from the material composition and structural configuration required to withstand the load conditions it experiences during the vehicle operation. Mass estimating relations (MERs) are often used to estimate the vehicle structural weight in relation to geometric parameters of the vehicle. MERs created from data available from existing vehicles are only valid for the load conditions experienced by those particular vehicles and they may not take into account the variation in load conditions due to a vehicle’s trajectory or weight. The vehicle structural weight can also be determined using multi-dimensional finite element (FE) models. Though this high-fidelity technique provides very accurate results, the creation, preparation, and analysis of complex FE models to predict structural weight can require a large amount of computational effort and can also be very time consuming.
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    Design, Modeling, and Simulation of a Hydrogen-Induced Air Liquefaction System Applicable to Space Access Vehicles
    (Georgia Institute of Technology, 2004-02-05) Crowley, John E.
    Air liquefaction has been advocated as a concept for reducing the gross mass of spaceplanes since the 1950s. However, little has come of this promising technology thus far. The purpose of air liquefaction is to use cryogenic propellants to supercool air after it enters the inlet of a moving vehicle. The resulting liquefied air can be used immediately or stored for use in later stages of flight. Although the concept has been revisited multiple times since its inception, various problems have surfaced to keep it from being a viable technology for incorporation into an access-to-space vehicle. Among the many design challenges, one of these problems is the formation of solid ice due to the freezing of water in the humid air. This ice fouls heat exchanger surfaces and results in decreased efficiency and eventually total shut-down of the engine. Therefore, a system to dehumidify the air before it is used as an oxidizer or stored is necessary.