Design of Engine Exhaust-Washed Structures for an Efficient Supersonic Air Vehicle MDO Application

Structural components located aft of embedded engines on low observable aircraft, known as engine exhaust-washed structures (EEWS), are exposed to an extreme, configuration specific, combined thermal/structural loading environment. As a result of this operating environment, and the unique design challenges it poses, the effectiveness of EEWS designs is a key factor in the overall performance of an embedded engine aircraft. This means that design requirements and effects of overall configuration variability on exhaust structures must be addressed in early stages of a new embedded engine aircraft design to ensure that the final system can continue to meet performance requirements as development progresses. This paper highlights the design considerations for engine exhaust-washed structures design, steps taken to incorporate EEWS design requirements into a configuration-level design process of an efficient supersonic air vehicle (ESAV), as well as multidisciplinary design optimization methods developed that focus directly on structural design in a thermal/structural environment.