Implementation of a multi-level optimisation methodology within the e-design of a blended wing body

The modern requirement for low weight/high strength aircraft structures is placing an every increasing emphasise on the direct use of optimisation methods in the overall design process. In certain cases, such as that of the Blended Wing-Body (BWB) aircraft, the design cannot be successfully completed without the application of optimisation methods. This type of complex design has inevitably led to the growth in the size of the optimisation problem with large numbers of design variables and constraints being required in a design with strong interactions between the various structural components. Treating the problem in the conventional manner with all components considered simultaneously leads to excessive computer run times. In order to control this growth in problem size a multi-level approach has to be used in order to break down the problem into several sub-problems taking into account the structural coupling effects. Such an approach enables the use of parallel computer processing leading to a significant reduction of the computer run time and decreases the design cycle time.