In M.S. thesis No. 1, advantages of applying exergy-based analysis and optimization methods to the synthesis/design and operation of aircraft systems is demonstrated using a supersonic aircraft fighter flown over an entire mission. A first set of optimizations involving four objectives (two energy- based and two exergy-based) are performed with only propulsion and environmental control subsystem degrees of freedom. Losses for the airframe subsystem are not incorporated into the two exergy-based objectives. The results show that, as expected, all four objectives globally produce the same optimum vehicle. A second set of optimizations is then performed with airframe degrees of freedom. However, this time one of the exergy-based objectives incorporates airframe losses directly into the objective. The results are that this latter objective produces a significantly better optimum vehicle. Thus, an exergy-based approach is not only able to pinpoint where the greatest inefficiencies in the system occur but seems to produce a superior optimum vehicle as well by accounting for irreversibility losses in subsystems only indirectly tied to fuel usage. No studies to date of which we are aware demonstrate the technology through an entire mission in which multiple flight conditions and constraints are encountered. Consequently, in M.S. theses No. 2 and No. 3, 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 energy-based methods of assessing highly integrated systems. The mission-level analysis provides much insight into the dynamics of mission-level hypersonic flight and demonstrates the usefulness of an exergy destruction minimization measure for highly integrated synthesis/design.
Use of Exergy and Decomposition Techniques in the Development of Generic Analysis, and Optimization Methodologies Applicable to the Synthesis/Design of Aircraft/Aerospace Systems
2006
73 pages
Report
No indication
English
Aircraft , Astronautics , Unmanned Spacecraft , Methodology , Optimization , Aerospace systems , Aircraft design , Decomposition , Integrated systems , Hypersonic vehicles , Supersonic aircraft , Supersonic combustion ramjet engines , Design criteria , Synthesis , Theses , Exergy analysis , Integrated mission level analysis optimization , Large-scale optimization , Scramjet(Supersonic combustion ramjet)
Adopting exergy analysis for use in aerospace
Online Contents | 2017
|Adopting exergy analysis for use in aerospace
Elsevier | 2017
|