University of Pisa
Thursday, June 11, 2015, 16:00 - 17:00
Room 01-012, Georges-Köhler-Allee 102, Freiburg 79110, Germany
There is currently great interest in innovative aircraft configurations which possibly could lead to a reduction of fuel consumption and an improvement of performances (with no increment of weight). Among them Joined-Wing concept has captured the attention as a possible candidate layout.
It is reasonable to wonder about the importance of their inherent structural nonlinearities that may invalidate the results obtained with fast lower-fidelity tools; moreover these nonlinearities are thought to be concerning when the deformation of the wing is significant. This is a feature of modern aircrafts, where weight reduction has brought to an increase of flexibility.
Dynamic (time-domain) solvers with different degrees of accuracy are described.
The fluid-structure interaction problem is firstly presented, along with the aerodynamic models adopted and the algorithms used for the interface (Infinite Plate Spline and Moving Least Square shape functions).
Results are then shown, focusing on the flutter occurrence and analyzing postcritical phenomena: Limit Cycle Oscillations (LCOs) are observed followed sometimes by a lost of periodicity of the solution as speed is further increased.
The complex scenario arising from the aeroelastic response of Joined-Wings is particularly evident in the inception of different bifurcations leading to multistability when a meaningful parameter (for example the speed in this analysis) is varied.