Adjoint-based method for supersonic aircraft design using equivalent area distribution

Abstract

This paper describes the efforts in the development of new adjoint-based techniques for the design of supersonic aircraft that must match a target equivalent area distribution at constant lift coefficients. This specific approach is meant to be part of a larger effort to create multidisciplinary analysis and optimization capabilities that can be used to design low-boom supersonic aircraft with adequate aerodynamic and structural performance. The paper focuses on the description of an inverse equivalent area distribution capability that includes the flow analysis, the formulation and implementation of an adjoint solver for the equivalent area distribution, and the shape design process of a trijet supersonic aircraft. This shape design effort is challenging due to three factors: the complexity of the geometric details involved that require a full unstructured flow and adjoint solver methodology, the apriori grid adaptation process needed for capturing the shock and expansion waves in the near-field (without the need for additional mesh adaptation), and the selected objective function for the calculation of sensitivities and the ultimate application in aircraft design. The viability of our approach is demonstrated with some preliminary examples. Ongoing work is targeting actual configurations that can result in an actual low-boom aircraft.

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“…18,19,20 In this study, the selective application of these techniques allows the removal of a lift constraint term that was previously included in Eq. 1.…”

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The conical deformation of a delta wing with sonic leading edges

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