Conceptual Design Optimisation of a Flying V Aircraft

Abstract

In the past decades, there has been an increasing awareness of the need for more environmentally­ friendly passenger aircraft. The lack of a feasible roadmap to carbon-­neutral air traffic, especially for long-­range flights, using the traditional tube-­and-wing form factor shows that a disruptive technology is necessary to bridge this gap. The Flying V is a newly proposed aircraft configuration which promises to enable a leap in long-­range passenger aircraft efficiency. Integration of passengers and cargo within the wing allows for a design which is more efficient both aerodynamically thanks to the lack of the non-­lifting fuselage, and structurally since the weight is distributed more in line with the lift distribution, reducing the need for long load­-paths. This study aims to evaluate the entire Flying V concept, integrating several disciplines. Building on the lessons learned from previous in­-depth studies into the separate disciplines, a performance model is constructed for the overall aircraft, resulting in an estimate of important characteristics of the complete aircraft, mainly a 31% decrease in mission fuel burn compared to the latest generation of long-­range conventional aircraft with a maximum takeoff weight reduction of 21%. Subsequently, a design optimisation aimed at minimising mission fuel burn is executed using the developed performance model, resulting in an updated design for the Flying V concept achieving a 35% decrease in mission fuel burn with a reduction in maximum takeoff weight of 25% compared to the same conventional aircraft. This optimised design features a narrower but longer cabin as compared to the baseline Flying V, which necessitates a modified cabin layout with 9­abreast seating in a 3­3­3 configuration instead of the 10­abreast 3­4­3 configuration of the baseline. This adjustment distributes the payload over the span to a greater extent, improving the match between the lift and weight distributions. Additionally, the sweep of the inner wing is decreased, with the constraint on both inner and outer wing sweep active. This shows that the wave drag of this configuration on both the inner and the outer wing is an important aspect of this design in terms of impact on the mission performance.