An Integrated Methodology To Improve The Design Of Wings

The design of high performance wing, especially those for car races, requires a methodology able to take into account many aspects at the same time. In many practical cases these aspects have to be modelled together in order to appreciate the way many causes interact and affect the global performance. In this paper the authors explain a methodology concerning an integrated CAD-FEM-CFD approach to study wing aerodynamics under deformations. Although CFD plays an important role in the design of shape of wing, in many cases the bodies impacted by the fluids are assumed to be rigid; structural deformations can often change the nominal shape of the wing and modify the fluid-dynamics performances of the system. In race car competitions this behaviour is welcome if with the increasing of vehicle speed the angle of attack decreases and both the drag and downforce decrease too. In many regulations this effect is forbidden and wing deformation under aerodynamics load has to be kept under an established limit. The proposed methodology couples CFD analyses with a discrete upgrading of geometry according with the FEM results. The implemented algorithm automatically transfers the pressure field coming from fluid-dynamics solution to FEM solver to obtain the deformation of the entire structure. This deformation is used to update the wing profile geometry and the CFD mesh all over the control volume. Data exchanging and iteration process ends when the deformations of two consecutive steps are smaller than a given error value. The practice shows that it happens quite quickly within three or four iterations. The parameterization of mesh updating has been also tested for studying how assembly errors affect aerodynamics performance. The methodology has been successfully tested on a high performance car front wing and interesting results have been reached.