Economics Models in MDO for Commercial Aircraft Design

The balance between performance and cost in commercial aircraft design is increasingly important, at both the conceptual and the preliminary design level. Airplane design has traditionally been driven strongly by weight considerations; however, engineers are increasingly expected to trade off weight against cost to find the “best-value” design. Value can be defined in many ways as appropriate for a particular program, but is progressively becoming identified with lifecycle cost. While tools (such as MDO) for predicting engineering performance or weight are well developed, physics-based and accurate, the cost models are generally very crude, and are based almost exclusively on high-level, empirical data. Accurate trade studies cannot be achieved when the fidelity of the models is so disparate.

This research begins to address these issues by developing an integrated cost/performance design tool. The work is directed towards new aircraft concepts, such as the Blended-Wing-Body, and focuses on the augmentation of the MDO framework to include cost models in a quantitative manner. Sophisticated methods from financial engineering, which build on real options theory, are combined with design optimization to create a rigorous methodology that integrates performance and finance in the design process.

Publications
Markish, J. and Willcox, K., “Value-Based Multidisciplinary Techniques for Commercial Aircraft System Design,” AIAA Journal, Vol. 41, No. 10, October 2003, pp. 2004-12.

Markish, J. and Willcox, K., “A Value-Based Approach for Commercial Aircraft Conceptual Design,” in Proceedings of the ICAS2002 Congress, Toronto , September 2002.

Markish, J. and Willcox, K., “Multidisciplinary Techniques for Commercial Aircraft System Design,” AIAA Paper 2002-5612, presented at the 9th AIAA symposium on Multidisciplinary Analysis and Optimization, Atlanta ,GA , September 2002.

Peoples, R. and Willcox, K., “Value-Based Multidisciplinary Optimization for Commercial Aircraft Design,” presented at the 45th AIAA Structures, Structural Dynamics and Materials conference, April 2004, Palm Springs, CA.