Simultaneous Optimization of a Multiple-Aircraft Family

Multidisciplinary design optimization is considered in the context of designing a family of aircraft. Aframework is developed in which multiple aircraft, each with different missions but sharing common parts, can be optimized simultaneously.Thenewframeworkisusedtogaininsighttotheeffectofdesignvariablescalingontheoptimization algorithm. Results are presented for a two-member family whose individual missions differ signie cantly. Both missions can be satise ed with common designs. Moreover, optimizing both airplanes simultaneously rather than following the traditional baseline plus derivative approach vastly improves the common solution. A cost modeling framework is outlined that allows the value of commonality to be quantie ed for design and manufacturing costs. A notional example is presented to show the cost benee t that may be achieved by designing a common family of aircraft.