Toward structural modelling strategies for characterization of future airframe – propulsion system interactions

Unconventional aircraft configurations which have been proposed to facilitate achievement of sustainable aviation goals are anticipated to display more significant interactions between the airframe and major sub-systems than conventional Tube-And-Wing aircraft. The design of such configurations is likely to be dictated by the configuration of major sub-systems, such as the propulsion system, and vice versa. Existing design methodologies do not readily accommodate the design of unconventional configurations due to reliance on empirical data derived from conventional Tube-And-Wing configurations. Consequently, the industry is largely uninformed regarding potentially significant variation in structural performance requirements of unconventional configurations relative to conventional configurations. The capability to generate representative analysis models during early design stages enables evaluation of structural attributes and requirements, assessed via key structural performance metrics, promoting an understanding of interactions which may exist between the airframe and major sub-systems. This paper details identification of key structural attributes and performance metrics for propulsion systems, and subsequent evaluation of contemporary modelling and analysis strategies. This work will inform development of a generic modelling and analysis framework to investigate the influence of propulsion system design parameters e.g. location, mass and integration strategy on key structural airframe performance metrics e.g. maximum operational loads and vice versa. As an important first step in validating the overall approach, the framework has been applied to a reference conventional Tube-And-Wing aircraft (Boeing 777-200LR) for which significant public domain data exists. Future research focuses on identification of generic structural idealization strategies which are appropriate for a range of airframe – propulsion system configurations.