Title page for ETD etd-52397-165523


Type of Document Master's Thesis
Author Golovidov, Oleg
Author's Email Address olgol@aoe.vt.edu
URN etd-52397-165523
Title Variable-Complexity Approximations for Aerodynamic Parameters in Hsct Optimization
Degree Master of Science
Department Aerospace and Ocean Engineering
Advisory Committee
Advisor Name Title
Grossman, Bernard M.
Watson, Layne T.
Mason, William H. Committee Chair
Keywords
  • range
  • aircraft
  • drag
Date of Defense 1997-06-18
Availability unrestricted
Abstract
A procedure for generating and using polynomial approximations to the range or to the cruise drag components in terms of 29 design variables for the High Speed Civil Transport (HSCT) configuration and performance design is presented.

Response surface model methodology is used to fit quadratic polynomials to data gathered from a series of numerical analyses of different HSCT designs. Several techniques are employed to minimize the number of required analyses and to maintain accuracy. Approximate analysis techniques

are used to find regions of the design space where reasonable HSCT designs could occur and response surface models are built using higher fidelity analysis results of the designs in this "reasonable" region. Regression analysis and analysis of variance are then used to reduce the number of polynomial terms in the response surface model functions.

Optimizations of the HSCT are then carried out both with and without the response surface models, and the effect of the use of the response surface models is discussed. Results of the work showed that considerable reduction of the amount of numerical noise in optimization is achieved with response surface models and the convergence rate was slightly improved. Careful attention was required to keep the accuracy of the models at an acceptable level.



NOTE: (07/2012) An updated copy of this ETD was added after there were patron reports of problems with the file.

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