OPTIMISATION OF A WING-BODY-TAIL CONFIGURATION WITH AN ALTERNATIVE LOW DRAG FUSELAGE AND BODY TRAILING EDGE

摘要

A wing-body-tail (WBT) configuration is proposed without the conventional tailplane, allowing for new requirements for the aerodynamic shape of the fuselage. A shorter, low drag body can be employed with a deflector trailing edge (Kutta edge/KE) to modify the flow around the body so as to allow wing-body circulation to be more uniform. Initial experimental and numerical work indicates benefits from both the low drag body profiles, as well as the addition of the deflector plate. The design space for such a deflector plate for the proposed WBT has not been explored. Therefore, the purpose of this study was to use an optimisation procedure to vary the aftbody deflection and KE shape to produce an optimum aerodynamic efficiency (L/D). The geometry varies by changing the KE spread angle and length, and deflecting the aftbody to optimise the WBT at Reynolds numbers of 1×10~5, with the wing at a fixed α = 6°, to determine whether a unique combination of these three parameters exists. Finally, the body is replaced with a low drag body, F-57 and KE shapes and aftbody deflections are optimised again. This work indicates a greater sensitivity to KE spread to achieve the best L/D than the other design variables. However, at a higher KE spread, L/D is increasingly affected by the other two variables.