The Blended-Wing-Body (BWB) is a recent airplane concept that shares similarities with both flying wings aircraft and Tube-And-Wings (T&W) aircraft. This concept presents various benefits with respect to conventional aircraft such as lowered fuel consumption and lowered noise emissions. Numerous studies have studied the reasons for those benefits but only a few have taken into account the stability of the plane despite its inherent instability. Indeed, most of those efficiency gains are due to the deletion of the stabilizer and this alteration diminishes the stability of the plane. Moreover, a majority of those studies have focused on long-range aircraft since the best efficiency gain, when compared to T&W aircraft, is encountered on transoceanic flights.
For those reasons, this study focused on the stability study of a 100 passengers BWB. To study the impact on stability various changes will have, nine configurations were produced and analysed. Finally, those changes were combined altogether to produce a configuration as stable as possible.
To start off, the Flying Qualities Requirements (FQR) are presented as the airplane’s stability will be evaluated based on those certification constraints. Next, Athena Vortex Lattice (AVL) is selected as the numerical analysis software used to study the plane’s behaviour in flight. Then a method allowing us to use AVL’s results to evaluate the stability of the plane and compare it to the FQR is established. This method is then used on the nine configurations allowing us to study the effect on stability of the various changes implemented.
The first results indicates that the plane is initially unstable in two of the three static stability modes and two of the five dynamic stability modes. The ninth configuration is however, stable in all three static stability modes and four out of the five dynamic stability modes. The initial configuration was stable in the fifth dynamic stability mode but the plane doesn’t need to be stable in this mode to be certified. Nonetheless, the plane doesn’t attain the best certification level in three of the eight FQR criterion.
| Date | 29 May 2017 |
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| Original language | French |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | François Morency (Supervisor) |
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Delecroix, T. (Author),
Morency (Supervisor),
29 May 2017Student thesis: Master's thesis › Master in Engineering: Engineering