Transport Weight Reduction Through MDO: The Strut-Braced Wing Transonic Transport

Abstract

Multidisciplinary Design Optimization (MDO) has been used to investigate the use of a new concept for a transonic transport, the strut-braced wing. The incorporation of a strut into more traditional transonic transport concepts required the application of computational design techniques that had been developed at Virginia Tech over the previous decade. Formalized MDO methods were required to reveal the benefits of the tightly coupled interaction between the wing structural weight and the aerodynamic performance. To perform this study, a suite of approximate analysis tools was assembled into a complete, conceptual-level MDO code. A typical mission of the Boeing 777-200IGW was chosen as the design mission profile. Several single-strut configurations were optimized for minimum takeoff gross weight, with the best single-strut configuration showing a nearly20% reduction in takeoff gross weight, a 29% reduction in fuel weight, a 28% increase in the lift-to-drag ratio, and a 41% increase in seat-miles per gallon relative to a comparable cantilever configuration. The use of aeroelastic tailoring in the design illustrated ways to obtain further benefits. The paper synthesizes the results of the five-year effort, and concludes with a discussion of the effects various constraints have on the design, and lessons learned on computational design during the project.

Multidisciplinary Design Optimization of Subsonic Strut-Braced Wing Aircraft

“…The analyses are performed by in-house codes which are linked to the ModelCenter interface via C++ or Python plugins known as Wrappers. Details about the various wrappers and their purposes have been explained in detail in previous studies [4][5][6][7][8][9][10] . The aircraft is designed for 17 load cases, which represent various flight conditions as shown in Table 1.…”

“…1. Following Pfenninger's ideas, the concept of strut-braced wing (SBW) and TBW configurations for long and medium-range civilian transport aircraft has been investigated using multidisciplinary design optimization (MDO) approach [4][5][6][7][8][9][10] . These studies clearly established the potential benefits of such configurations in reducing take-off gross weight (TOGW) and/or fuel consumption.…”

Tradeoffs of Wing Weight and Lift/Drag in Design of Medium-Range Transport Aircraft

“…The TBW concept for a Mach 0.85, long-range transport like the Boeing 777-200ER has been extensively studied at Virginia Polytechnic Institute and State University (Virginia Tech) using multidisciplinary design optimization (MDO) tools [6][7][8][9][10][11]. Here, we will consider medium-range transports similar to the Boeing 737-800 and Airbus A320.…”

Aerodynamic Considerations in the Design of Truss-Braced-Wing Aircraft

“…1. Following Pfenninger's footsteps [4], the concept of a strut-braced-wing (SBW) configuration was investigated using multidisciplinary design optimization (MDO) tools [5][6][7]. These studies established the potential benefits of such configurations.…”