A case for multi-level optimisation in aeronautical design

This paper discusses how the inevitable limitations of computing power avai lable to designers has restricted adoption of optimisation as an essential design tool. It is argued that this situation will continue until optimisat ion algorithms are developed which utilise the range of available analysis methods in a manner more like human designers. The concept of multi-level a lgorithms is introduced and a case made for their adoption as the way forwa rd. The issues to be addressed in the development of multi-level algorithms are highlighted. The paper goes on to discuss a system developed at Southampton University t o act as a test bed for multi-level algorithms deployed on a realistic desi gn task. The Southampton University multi-level wing design environment int egrates drag estimation algorithms ranging from an empirical code to an Eul er CFD code, covering a 150,000 fold difference in computational cost. A si mple multi-level optimisation of a civil transport aircraft wing is present ed.