This study utilizes Multidisciplinary Design Optimization (MDO) techniques to explore the effectiveness of the truss-braced (TBW) and strut-braced (SBW) wing configurations in enhancing the performance of medium range, transonic transport aircraft. The truss and strut-braced wing concepts synergize structures and aerodynamics to create a planform with decreased weight and drag. Past studies at Virginia Tech have found that these configurations can achieve significant performance benefits when compared to a cantilever aircraft with a long range, Boeing 777-200ER-like mission. The objective of this study is to explore these benefits when applied to a medium range Boeing 737-800NG-like aircraft with a cruise Mach number of 0.78, a 3,115 nautical mile range, and 162 passengers.

Results demonstrate the significant performance benefits of the SBW and TBW configurations. Both configurations exhibit reduced weight and fuel consumption. Configurations are also optimized for 1990's or advanced technology aerodynamics. For the 1990's technology minimum TOGW cases, the SBW and TBW configurations achieve reductions in the TOGW of as much as 6% with 20% less fuel weight than the comparable cantilever configurations. The 1990's technology minimum fuel cases offer fuel weight reductions of about 13% compared to the 1990's technology minimum TOGW configurations and 11% when compared to the 1990's minimum fuel optimized cantilever configurations. The advanced aerodynamics technology minimum TOGW configurations feature an additional 4% weight savings over the comparable 1990's technology results while the advanced technology minimum fuel cases show fuel savings of 12% over the 1990's minimum fuel results. This translates to a 15% reduction in TOGW for the advanced technology minimum TOGW cases and a 47% reduction in fuel consumption for the advanced technology minimum fuel cases when compared to the simulated Boeing 737-800NG. It is found that the TBW configurations do not offer significant performance benefits over the comparable SBW designs.