Simultaneous Optimization of a Multiple-Aircraft Family

Multidisciplinary design optimization is considered in the context of designing a family of aircraft. A framework is developed in which multiple aircraft, each with different missions but sharing common parts, can be optimized simultaneously. The new framework is used to gain insight to the effect of design variable scaling on the optimization algorithm. Results are presented for a two-member family whose individual missions differ signicantly. Both missions can be satised with common designs. Moreover, optimizing both airplanes simultaneously rather than following the traditionalbaseline plus derivative approach vastly improvesthe common solution. A cost modeling fra mework is outlined that allows the value of commonality to be quantied for design and manufacturing costs. A notional example is presented to show the cost benet that may be achieved by designing a common family of aircraft.