Increasing air traffic demand and the resulting climate impact of aircraft emissions are of growing public concern. Considering the future impact of commercial aviation in terms of economic and environmental sustainability requires not only the design of efficient new aircraft for a single market, but also consideration of the operational use and the flexibility of these aircraft during the design stage. The requirements for aircraft, in terms of design range and capacity, in different markets, such as in North America, Europe or China, and even between operators in the same market can be substantially different or even conflicting. Even so the design of new aircraft takes these differing requirements into account; the design process is only loosely coupled with the use of these aircraft by operators around the world [1]. Any given aircraft is rarely operated at its design mission, which can result in operational inefficiencies.
Previous research [2, 3, 4] has concentrated on the design optimization of a single new aircraft using simple analytical models in connection with the optimization of the route assignment of the given aircraft for a specific network, or including the design of the network, for operating cost. It was shown that incorporating coupling through the aircraft operations between the aircraft design and aircraft allocation can significantly reduce the operating costs for a given network.
Single new aircraft lack the flexibility to address varying requirements for different markets. Additionally, the cost of developing and producing new aircraft is substantial. Using a product family approach in the design of an aircraft family, with shared common components, allows these different market needs and design requirements to be met, while providing operational benefits, increased flexibility and cost savings [5, 6]. From a manufacturer's point of view, product families cater to the varying needs of potential customers by offering a wider selection of aircraft at a lower development and production cost [7].
In order to explore the trade-offs involved in designing efficient, environmentally sustainable aircraft, a coupled robust design optimization involving uncertainties in the growth of passenger demand over multiple years of operations was conducted. Including operational assignment of aircraft in the design stage aims at reduce operational inefficiencies, while the design of an aircraft family aims at reducing cost.
Application of the above approach for a North American and European representative route networks showed that the coupled design of aircraft families with the allocation of these aircraft to these distinct markets can significantly reduce fuel burn, operating and acquisition cost compared to currently existing aircraft. The reductions in fuel burn result in corresponding reductions in emissions and increased environmental sustainability. These aircraft also provide higher flexibility and improved performance when compared against aircraft obtained from a robust design optimization approach, where each aircraft is optimized individually and decoupled from the fleet allocation.
References
1. M. Mane and W.A. Crossley, “Allocation and Design of Aircraft for On-demand Air Transportation with Uncertain Operations”, Journal of Aircraft, Vol. 49, No. 1, 2012, pp. 141 – 150.
2. P. Govindaraju and W.A. Crossley, “Profit Motivated Airline Feet Allocation and Concurrent Aircraft Design for Multiple Airlines”, 13th AIAA Aviation Technology, Integration, and Operations Conference (ATIO), Los Angeles, CA, August 2013.
3. S. Lehner, T. Zill, and Go, “Using Aircraft Requirements as Variables: An Integrated Optimization Approach for Air Transportation System”, 12th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference, Indianapolis, Indiana, September 2012.
4. G. Marwaha and M. Kokkolaras, “System-of-Systems Approach to Air Transportation Design using Nested Optimization and Direct Search”, Structural and Multidisciplinary Optimization, 2014, pp. 1 – 17.
5. Perez, R.E., and Behdinan K., A Multidisciplinary Design Optimization Approach to Aircraft Family Design, Canadian Aeronautics and Space Institute AERO Conference, Toronto, Ontario, 2007.
6. J. Allison, B. Roth, M. Kokkolaras, I. Kroo, and P. Y. Papalambros. “Aircraft Family Design Using Decomposition-based Methods”. In 11th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, Portsmouth, Virginia, September 2006.
7. Asikoglu, O. and Simpson, T.W., “A New Method for Evaluating Design Dependencies in Product Architectures”. 12th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference, Indianaplois, Indiana, September 2012.
Topics: Design automation and optimization , Topics: Design-to-cost and value engineering
