A Parametric Design Process based on Optimization-Guided Incremental Design Decisions

The traditional aircraft design process is typically split into three stages: conceptual, preliminary, and detailed design. This three-stage process usually proceeds sequentially from stage to stage, and major design decisions are frozen between stage transitions. But this model does not capture the more complex reality, where design decisions are subject to frequent iteration at all stages of the process. This paper presents the Engineering Sketch Pad (ESP) Phasing capability that captures this more complex design workflow by decomposing the process into atomic portions called Phases. Each phase is intended to branch from any completed phase and answer a specific design question, allowing the designer to make design decisions non-sequentially. The use of this Phasing capability is demonstrated with the sizing of an aircraft wing while simultaneously optimizing an airfoil with increasing aerodynamic and geometric model fidelity. A number of cases are presented, beginning with a low fidelity aerodynamic model and a NACA 24XX airfoil geometry, and culminating in a Kulfan CST4 representation of geometry with MSES to perform the airfoil analysis.