Multidisciplinary optimization of high-speed civil transport configurations using variable-complexity modeling

Abstract

An approach to aerodynamic configuration optimization is presented for the high-speed civil transport (HSCT). Methods to parameterize the wing shape, fuselage shape and nacelle placement are described. Variable-complexity design strategies are used to combine conceptual and preliminary-level design approaches, both to preserve interdisciplinary design influences and to reduce computational expense. The preliminary-design-level analysis methods used to estimate aircraft performance are described. Conceptual-design-level (approximate) methods are used to estimate aircraft weight, supersonic wave drag and drag due to lift, and landing angle of attack. The methodology is applied to the minimization of the gross weight of an HSCT that flies at Mach 2.4 with a range of 5500 n.mi. Results are presented for wing plan form shape optimization and for combined wing and fuselage optimization with nacelle placement. Case studies include both all-metal wings and advanced composite wings. The results indicate the beneficial effect of simultaneous design of an entire configuration over the optimization of the wing alone and illustrate the capability of the optimization procedure.