Aerodynamics of Civil Transport Supersonic Aircraft Multi-disciplinary Design Optimisation of High-Speed Civil Transport Aircraft Wing Planform
Example of multi-disciplinary analyses performed in CISAP
(for the optimised Mach 2.0 aircraft configuration).
The CFD results are illustrated on the right wing and the results of the FE calculation
are presented on left wing for internal wing structural elements.
Onera participated to the EREA-Airbus pilot-project CISAP, in collaboration with DLR, NLR and QinetiQ. CISAP, acronym of " Cruise speed Impact on Supersonic Aircraft wing Planform " is a project intended to study how the optimum wing shape of a High-Speed Civil Transport (HSCT) aircraft evolves with the cruise Mach number.
Within CISAP, the Applied Aerodynamics Department has developed a complete multi-disciplinary optimisation (MDO) system enabling automated wing planform optimisations. The design of wings for supersonic aircraft is a challenging and really multi-disciplinary task due to its low thickness-to-chord ratio, which yields a strong coupling between aerodynamics and structures. These two disciplines, which are anticipated to be the actual design drivers, have thus been modelled in this MDO process with high fidelity methods, respectively CFD (Computational Fluid Dynamics) calculation with the elsA software for aerodynamics and FE (Finite Elements) calculation for the wing structure sizing.
Flowchart of the Onera MDO process developed within CISAP
for optimisation of supersonic aircraft wing planform. Larger Image
This MDO system has then been applied to optimise two aircraft concepts, one for a cruise Mach number of 2.0 and the second for a cruise Mach number of 1.3. The optimisation of the M=2.0 aircraft has been performed with a gradient based method and yielded a 11% improvement of the range of the datum design, derived from the ESCT configuration and used as starting point for this optimisation. The M=1.3 optimisations have been conducted in two stages, involving successively Genetic Algorithm and gradient-based optimisers. These last optimisations permitted a range improvement of 17% over the datum aircraft.
The demonstration of the MDO techniques and the results therefrom help Airbus consider the methods by which future aircraft could be designed, and the potential advantages of novel planforms for different cruise speeds.
