Design under Uncertainties of Wings in Transonic Field(<Special Issue>Advanced Fluid Information)

In this paper we illustrate a new method for design of wings based on the optimization of the performance stability. This technique is an alternative approach to the traditional one which considers just a design point and tends to "over-optimize", producing solutions that perform well at the design point but have poor off-design characteristics. This method has been implemented for wing design in transonic field, searching for solutions that are stable in terms of performance with the fluctuations of Mach number and angle of attack. The high fidelity simulation has been performed with a Navier-Stokes code and a multi objective genetic algorithm has been used to optimize; in fact it has been proved that the design of airfoils, where the performance (lift and drag) and the stability are both objectives, is implemented more efficiently using a multi objective approach. In the optimization phase in order to reduce the number of needed simulations a response surface based on statistics (DACE) will be used.