Scholarly
    Communications Project


Document Type:Master's Thesis
Name:Oleg Golovidov
Email address:olgol@aoe.vt.edu
URN:
Title:VARIABLE-COMPLEXITY APPROXIMATIONS FOR AERODYNAMIC PARAMETERS IN HSCT OPTIMIZATION
Degree:Master of Science
Department:Aerospace and Ocean Engineering
Committee Chair: William H. Mason
Chair's email:mason@aoe.vt.edu
Committee\ Members:
Keywords:aircraft, range, drag
Date of defense:June 18, 1997
Availability:Release the entire work immediately worldwide.

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.

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Oleg.thesis.pdf


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