Computer Science Technical Reports
CS at VT

Noisy Aerodynamic Response and Smooth Approximations in HSCT Design

Giunta, Anthony A. and Dudley, J. and Narducci, Robert and Grossman, Bernard and Haftka, Robert T. and Mason, William H. and Watson, Layne T. (1994) Noisy Aerodynamic Response and Smooth Approximations in HSCT Design. Technical Report ncstrl.vatech_cs//TR-94-29, Computer Science, Virginia Polytechnic Institute and State University.

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Convergence difficulties were encountered in our recent efforts towards a combined aerodynamic-structural optimization of the High Speed Civil Transport (HSCT). The underlying causes of the convergence problems were traced to numerical noise in the calculation of aerodynamic drag components for obstacles to convergence. The first technique employed a sequential approximation optimization method which used large initial move limits on the design variables. This helped dislodge the optimizer out of the local minima in the design space created by the noisy drag data. The second method utilized the aircraft. Two techniques were developed to circumvent the response surface methods to construct smooth approximations to the noisy data. The response surfaces were formed by analyzing several individual HSCT configuration and then fitting polynomial functions to selected objective function data. A simplified example design problem was used to demonstrate the response surface technique and to investigate various other issues relating to the construction of the response surfaces.

Item Type:Departmental Technical Report
Subjects:Computer Science > Historical Collection(Till Dec 2001)
ID Code:411
Deposited By:User autouser
Deposited On:05 December 2001
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