Fluid Structure Interaction on a Flexible Micro Air Vehicle

The interaction between the fluid and structure on an MAV can have a significant effect on the nature of the aerodynamic characteristics and stability of the vehicle. The aerodynamic twist can be designed into the wing through the use of a soft wing material, to adaptively increase the wing camber. This investigation is concerned with the deformation of a depron-foam flying wing MAV under aerodynamic loading. Depron foam shows a moderate rigidity which is neither too rigid as carbon fibre nor too soft as a membrane skin. The proper deformation at wingtip under the aerodynamic loading forms a desirable dihedral angle which can deform into a proper designed dihedral angle and improve rolling stability. In the study, carbon fibre rods were attached underneath the wing to improve wing strength in order to form a desired dihedral angle. The aerodynamic performance of the strengthen wing has shown that the desired deformation increases as the incidence rises and causes a significant pressure redistribution which increases both lift and drag. Wing deformation also minimise the complex vortical flow on the upper wing surface, corresponding to a drag reduction.