Aircraft Design Optimization

The aim of this chapter is to offer an elementary introduction to approaches that have proven effective in conceptual design. The results of an optimization process are largely determined by the problem structure set up to carry out the automated process. This chapter begins by defining three classes of design parameters, explaining the difference between optimal control and discrete-variable optimization and between unconstrained and constrained optimization. Advantages and disadvantages of various single-objective optimization methods used in advanced aircraft design are discussed. It is argued that an efficient approach in the conceptual stage is a combination of non-complex explicit and complex multivariate optimization. The traditional optimization of a complete aircraft system consisting of sequential disciplinary activities resulted in sub-optimization and an inefficient development process. The method of multidisciplinary analysis and optimization exploits the synergism of interacting computational domains. This has thoroughly changed the way in which the design of complex engineering system is organized. Essential aspects of multidisciplinary optimization are system decomposition, multilevel and multi-objective optimization. Conditions for realistic and effective optimization in conceptual aircraft design are discussed and applied in the following chapters.