The Flying V is a long-range, flying-wing aircraft where payload and fuel both reside in a V-shaped, crescent wing with large winglets that double as vertical tail planes. The objective of this study is to maximize the lift-to-drag (?/7) ratio of the Flying V in cruise conditions
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The Flying V is a long-range, flying-wing aircraft where payload and fuel both reside in a V-shaped, crescent wing with large winglets that double as vertical tail planes. The objective of this study is to maximize the lift-to-drag (?/7) ratio of the Flying V in cruise conditions, i.e. 6? = 0.26, @ = 0.85 and to investigate its off-design performance in high-subsonic conditions. This is done by manually modifying the design parameters that describe the outer mold line of the Flying V and assessing the aerodynamic performance by means of computational fluid
dynamics. A 15-million cell, third-order MUSCL, Reynolds-Averaged Navier Stokes solver with the Menter SST turbulence model is used to estimate the aerodynamic coefficients. A new, CATIA-based, parametrization of the Flying V is the starting point of the design. Three manual design phases improve the aerodynamic performance while satisfying all constraints. Design
modifications included an increase in camber and aft-loading of the wing around 40% of the semispan and improved airfoil sections on the outboard wing generating the required lift coefficient towards an elliptical lift distribution. The twist distribution at the wing-winglet junction is optimized to reduce wave drag. This has resulted in an improvement of ?/7 from 21.3 for the baseline to 24.2 for the final version while reducing the cruise angle of attack from 5.2 to 3.6 degrees. The drag divergence Mach number is estimated at 0.925.
