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

Abstract

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.

Preliminary Performance Analysis of Medium-Range Liquid Hydrogen-Powered Box-Wing Aircraft

“…The optimization procedure was set up to size different possible onboard tank layouts, and to assess mission performance for box-wing configurations retrofitted with LH 2 propulsion. Since the external shape of the aircraft is kept the same as the baseline, and therefore the aerodynamic performance and airframe structural weight (excluding tanks) are fixed and known, the optimization procedure defined by Equations ( 7) and ( 8) mainly involve design variables related to tank integration, as defined in Table 4; specifically: max X(x) (7) over:…”

“…The demand for air travel continues to raise, driven by global connectivity and economic growth [1,2], but so does the imperative to reduce the industry's carbon footprint [3,4]. The pressing need to mitigate the environmental impact of aviation has accelerated the exploration of disruptive non-evolutionary solutions, both in the field of unconventional airframes [5,6] and alternative propulsion technologies [7]. Innovative configurations such as truss-braced wing [8,9], blended wing-body [10,11], and box-wing [12,13] have shown their potential to introduce improvements for aerodynamic and structural performance, and consequently to reduce fuel consumption per passenger transported.…”