Abstract :
It is suggested that it may be time to consider whether we have reached a plateau in terms of the evolutionary nature of flight vehicle design and optimization. For a time, progress was measured in terms of maximum speed, which is a straightforward metric when the next design is evolved from the preceding model. There are times, however, when we need to depart from the evolutionary process and create a breakthrough design. The question to be asked is whether there is any way to define system-level analysis and optimization techniques to facilitate the vehicle design process with a more global measure of effectiveness. This paper presents such a methodology for the design of the complete integrated system of systems. Work that has been done in energy-based methods is briefly reviewed, since energy is an implicit consideration in many aerospace disciplines. In addition, methods such as exergy and thermoeconomics have been applied in the design of ground power stations and they are currently being studied for application to aircraft subsystems. The objective of this paper is to expand exergy methods to the design of a complete flight vehicle by defining mission requirements as an exergy/work problem cascading down to each component in the same framework. This paper also serves to introduce a special section of this journal devoted to the application of exergy methods to all levels of flight vehicle design. Overall, the proposed technique provides a method to facilitate system-level optimization at all levels of the design process.
