The problem to define a methodology for the analysis of aircraft performances, in the phase of conceptual design, is addressed. The proposed approach is based on a numerical optimization procedure where a scalar objective function, the take-off weight, is minimized. Deterministic and stochastic approaches as well as hybridizations between these two search techniques are considered. More precisely, we consider two-stage strategies where the optimum localization is performed by a genetic algorithm, while a gradient-based method is used to terminate the optimization process. Also, another type of hybridization strategy is investigated where a partially converged gradient-based method is incorporated in the genetic algorithm as a new operator. A detailed discussion is made and various different solutions are critically compared.The proposed methodology is consistent and capable of giving fundamental information to the designer for further investigating towards the directions identified by the procedure.A basic example is described, and the use of the methodology to establish the effects of different geometrical and technological parameters is discussed.
NomenclatureA Sectional area of panel structure, m 2 AR aspect ratio b span, m c chord length, m c L global lift coefficient Springer 152 Optim Eng (2006) 7: 151-171 E efficiency (lift-to-drag ratio) g acceleration of gravity, m/s 2 H cruise altitude, m i root angle, deg L length, m l t distance between aerodynamic centers of wing and stabilizer, m M Mach number N population size N b best-fit individuals ng number of generations p vector of parameters pc probability of crossover pg probability of gradient pm probability of mutation R range at cruise velocity, km S surface area, m 2