Exergy Methods for the Mission-Level Analysis and Optimization of Generic Hypersonic Vehicles

Though the field of hypersonic vehicle design is thriving again, few studies to date demonstrate the technology through a mission in which multiple flight conditions and constraints are encountered. This is likely due to the highly integrated and sensitive nature of hypersonic vehicle components. C...

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Main Author: Brewer, Keith Merritt
Other Authors: Mechanical Engineering
Format: Others
Published: Virginia Tech 2014
Subjects:
Online Access:http://hdl.handle.net/10919/32007
http://scholar.lib.vt.edu/theses/available/etd-04282006-234758/
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spelling ndltd-VTETD-oai-vtechworks.lib.vt.edu-10919-320072020-09-26T05:37:37Z Exergy Methods for the Mission-Level Analysis and Optimization of Generic Hypersonic Vehicles Brewer, Keith Merritt Mechanical Engineering von Spakovsky, Michael R. Ellis, Michael W. O'Brien, Walter F. Jr. Moorhouse, David exergy hypersonic optimization scramjet Though the field of hypersonic vehicle design is thriving again, few studies to date demonstrate the technology through a mission in which multiple flight conditions and constraints are encountered. This is likely due to the highly integrated and sensitive nature of hypersonic vehicle components. Consequently, a formal Mach 6 through Mach 10 flight envelope is explored which includes cruise, acceleration/climb, deceleration/descend and turn mission segments. An exergy approach to the vehicle synthesis/design, in which trade-offs between dissimilar technologies are observed, is proposed and measured against traditional methods of assessing highly integrated systems. A quasi one-dimensional hypersonic vehicle system simulation program was constructed. Composed of two sub-systems, propulsion and airframe, mechanisms for loss are computed from such irreversible processes as shocks, friction, heat transfer, mixing, and incomplete combustion. The propulsion sub-system consists of inlet, combustor, and nozzle, while the airframe provides trim and force accounting measures. An energy addition mechanism, based on the potential of MHD technology, is utilized to maintain a shock-on-lip inlet operating condition. Thirteen decision variables (seven design and six operational) were chosen to govern the vehicle geometry and performance. A genetic algorithm was used to evaluate the optimal vehicle synthesis/design for three separate objective functions, i.e the optimizations involved the maximization of thrust efficiency, the minimization of fuel mass consumption, and the minimization of exergy destruction plus fuel exergy loss. The principal results found the minimum fuel consumption and minimum exergy destruction measures equivalent, both meeting the constraints of the mission while using 11% less fuel than the thrust efficiency measure. Optimizing the vehicle for the single most constrained mission segment yielded a vehicle capable of flying the entire mission but with fuel consumption and exergy destruction plus fuel loss values greater than the above mentioned integrated vehicle solutions. In essence, the mission-level analysis provided much insight into the dynamics of mission-level hypersonic flight and demonstrated the usefulness of an exergy destruction minimization measure for highly integrated synthesis/design. Master of Science 2014-03-14T20:34:32Z 2014-03-14T20:34:32Z 2006-04-21 2006-04-28 2006-05-26 2006-05-26 Thesis etd-04282006-234758 http://hdl.handle.net/10919/32007 http://scholar.lib.vt.edu/theses/available/etd-04282006-234758/ THESIS_FINISHED_word2_5-24-06.pdf In Copyright http://rightsstatements.org/vocab/InC/1.0/ application/pdf Virginia Tech
collection NDLTD
format Others
sources NDLTD
topic exergy hypersonic optimization scramjet
spellingShingle exergy hypersonic optimization scramjet
Brewer, Keith Merritt
Exergy Methods for the Mission-Level Analysis and Optimization of Generic Hypersonic Vehicles
description Though the field of hypersonic vehicle design is thriving again, few studies to date demonstrate the technology through a mission in which multiple flight conditions and constraints are encountered. This is likely due to the highly integrated and sensitive nature of hypersonic vehicle components. Consequently, a formal Mach 6 through Mach 10 flight envelope is explored which includes cruise, acceleration/climb, deceleration/descend and turn mission segments. An exergy approach to the vehicle synthesis/design, in which trade-offs between dissimilar technologies are observed, is proposed and measured against traditional methods of assessing highly integrated systems. A quasi one-dimensional hypersonic vehicle system simulation program was constructed. Composed of two sub-systems, propulsion and airframe, mechanisms for loss are computed from such irreversible processes as shocks, friction, heat transfer, mixing, and incomplete combustion. The propulsion sub-system consists of inlet, combustor, and nozzle, while the airframe provides trim and force accounting measures. An energy addition mechanism, based on the potential of MHD technology, is utilized to maintain a shock-on-lip inlet operating condition. Thirteen decision variables (seven design and six operational) were chosen to govern the vehicle geometry and performance. A genetic algorithm was used to evaluate the optimal vehicle synthesis/design for three separate objective functions, i.e the optimizations involved the maximization of thrust efficiency, the minimization of fuel mass consumption, and the minimization of exergy destruction plus fuel exergy loss. The principal results found the minimum fuel consumption and minimum exergy destruction measures equivalent, both meeting the constraints of the mission while using 11% less fuel than the thrust efficiency measure. Optimizing the vehicle for the single most constrained mission segment yielded a vehicle capable of flying the entire mission but with fuel consumption and exergy destruction plus fuel loss values greater than the above mentioned integrated vehicle solutions. In essence, the mission-level analysis provided much insight into the dynamics of mission-level hypersonic flight and demonstrated the usefulness of an exergy destruction minimization measure for highly integrated synthesis/design. === Master of Science
author2 Mechanical Engineering
author_facet Mechanical Engineering
Brewer, Keith Merritt
author Brewer, Keith Merritt
author_sort Brewer, Keith Merritt
title Exergy Methods for the Mission-Level Analysis and Optimization of Generic Hypersonic Vehicles
title_short Exergy Methods for the Mission-Level Analysis and Optimization of Generic Hypersonic Vehicles
title_full Exergy Methods for the Mission-Level Analysis and Optimization of Generic Hypersonic Vehicles
title_fullStr Exergy Methods for the Mission-Level Analysis and Optimization of Generic Hypersonic Vehicles
title_full_unstemmed Exergy Methods for the Mission-Level Analysis and Optimization of Generic Hypersonic Vehicles
title_sort exergy methods for the mission-level analysis and optimization of generic hypersonic vehicles
publisher Virginia Tech
publishDate 2014
url http://hdl.handle.net/10919/32007
http://scholar.lib.vt.edu/theses/available/etd-04282006-234758/
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