Aerodynamic shape optimization of a supersonic transport including a subsonic static margin constraint

Designing supersonic transport aircraft requires accounting for performance and stability at high-speed and low-speed conditions. Previous work demonstrated that there is a trade-off between high-speed performance and low-speed stability. Numerical optimization presents the opportunity to obtain the best high-speed performance while requiring stability at low speeds. We perform RANS-based aerodynamic shape optimization with a component-based geometry parameterization approach that enables the optimization of a three-surface supersonic transport configuration. We minimize drag at a supersonic cruise condition with and without a constraint on subsonic pitch stability. The stability constraint enforces a target static margin at a subsonic takeoff condition. The stable optimized designs use larger leading-edge flap deflections at the subsonic condition and have thicker wings. The thicker wings increase the supersonic drag by 0.5% for neutral stability and 0.85% for a 10% static margin. These results demonstrate that aerodynamic shape optimization is a valuable tool for designing supersonic transport aircraft accounting for supersonic performance and subsonic stability. • RANS-based optimization can design supersonic aircraft that are stable at low-speeds. • Stable designs use larger leading-edge flap deflections and have thicker wings. • The stable designs' thicker wings result in higher supersonic drag.