This thesis work shows the advantages of applying exergy-based analysis and optimization methods to the synthesis/design and operation an Advanced Aircraft Fighter (AAF) with three subsystems: a Propulsion Subsystem (PS), an Environmental Control Subsystem (ECS), and an Airframe Subsys-tem - Aerodyanmics (AFS-A) is used to illustrate these advantages. Thermodynamic (both energy and exergy), aerodynamic, geometric, and physical models of the components comprising the subsystems are developed and their interactions defined. An exergy-based parametric study of the PS and its components is first performed in order to show the type of detailed information on internal system losses. This is followed by a series of constrained, system synthesis/design optimizations based on five different objective functions, which define energy-based and exergy-based measures of performance.
A first set of optimizations involving four of the objectives (two energy-based and two exergy-based) are performed with only PS and ECS degrees of freedom. Losses for the AFS-A 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 AFS-A degrees of freedom and again with two energy- and exergy-based objectives. However, this time one of the exergy-based objectives incorporates AFS-A 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 produces a superior optimum vehicle as well by accounting for irreversibility losses in subsystems (e.g., the AFS-A) only indirectly tied to fuel usage. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/31405 |
| Date | 17 May 2005 |
| Creators | Periannan, Vijayanand |
| Contributors | Mechanical Engineering, von Spakovsky, Michael R., Moorhouse, David, Nelson, Douglas J., Ellis, Michael W. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | Vijay_Thesis.pdf |
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