Wave Drag Reduction for Aircraft Fuselages.
NORTHROP CORP HAWTHORNE CALIF AIRCRAFT DIV
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A numerical procedures has been developed to minimize the wave drag of a forward aircraft fuselage and canopy configuration subject to realistic constraints imposed by design requirements. The procedure makes use of the Latin Square sampling technique and the Three-Dimensional Method of Characteristics. The former is used to efficiently sample the family of configurations, and the latter is used to accurately calculate the wave drags of the sampled configurations. The calculated wave drag coefficients are then used to derive a functional dependence of the wave drag on the geometric variables that define the family of configurations. The minimum wave drag configuration can be obtained by minimizing the wave drag function subject to a given set of constraints. A new concept which enables the minimizing procedure to improve by learning from experience is presented. This concept proves very useful and can be applied to other optimization procedures using Latin Square sampling. Finally, the wave drag reduction procedure is demonstrated using the F-4 fuselage as the baseline. The results are presented and discussed. Author