A Review of Novel and Non-Conventional Propulsion Integrations for Next-Generation Aircraft

The aim of this review paper is to collect and discuss the most relevant and updated contributions in the literature regarding studies on new or non-conventional technologies for propulsion–airframe integration. Specifically, the focus is given to both evolutionary technologies, such as ultra-high bypass ratio turbofan engines, and breakthrough propulsive concepts, represented in this frame by boundary layer ingestion engines and distributed propulsion architectures. The discussion focuses mainly on the integration effects of these propulsion technologies, with the aim of defining performance interactions with the overall aircraft, in terms of aerodynamic, propulsive, operating and mission performance. Hence, this work aims to analyse these technologies from a general perspective, related to the effects they have on overall aircraft design and performance, primarily considering the fuel consumption as a main metric. Potential advantages but also possible drawbacks or detected showstoppers are proposed and discussed with the aim of providing as broad a framework as possible for the aircraft design development roadmap for these emerging propulsive technologies.