The Effect of Engine Location on the Aerodynamic Efficiency of a Flying-V Aircraft

The Flying-V is a novel flying wing concept where the main lifting surface has been fully integrated with the passenger cabin. This study focuses on the effect of engine positioning on aerodynamic interference under regulatory and structural constraints. An initial benchmark for the lift-to-drag ratio is obtained from a baseline Flying-V configuration, and the influence of the x, y and z position, as well as engine orientation are subsequently analysed. An Euler solver on a three-dimensional, unstructured grid is used to model the flow at cruise condition: M = 0.85, h = 13, 000 m, α = 2.9 ◦, and a thrust per engine of 50 kN. The viscous drag contribution is computed using an empirical method. A total of forty different engine locations are tested under these conditions to build a surrogate model that predicts the aircraft’s lift-to-drag ratio based on the position of the engine. The results obtained show that misplacing the engine can lead to significant lift-to-drag ratio losses going as high as 55% when compared against the ideal integration configuration. A region behind the airframe’s trailing edge is identified where the interference losses due to the installation are minimized. At this location, engine installation causes a 10% penalty in aerodynamic efficiency, a minimum one-engine-inoperative yawing moment and a small thrust-induced pitching moment.