Distributed propulsion and ultra-high by-pass rotor study at aircraft level

Abstract

This technical article discusses design and integration associated with distributed propulsion as a means of providing motive power with significantly reduced emissions and external noise for future aircraft concepts. The technical work reflects activities performed within a European Commission funded Framework 7 project entitled Distributed Propulsion and Ultra-high By-Pass Rotor Study at Aircraft Level, or, DisPURSAL. In this instance, the approach of distributed propulsion includes a Distributed Multiple-Fans Concept driven by a limited number of engine cores as well as one unique solution that integrates the fuselage with a single propulsor (dubbed Propulsive-Fuselage Concept) -both targeting entry-in-service year 2035+. Compared to a state-of-the-art, year 2000 reference aircraft, designs with tighter coupling between airframe aerodynamics and motive power system performance for medium-to-long-range operations indicated potentially a 40-45% reduction in CO 2 -emissions. An evolutionary, year 2035, conventional morphology gas-turbine aircraft was predicted to be -33% in CO 2 -emissions.

Conceptual Design of Operation Strategies for Hybrid Electric Aircraft

“…focuses on a broad spectrum of alternatives to conventional propulsion technologies and sources of energy for aircraft. In their investigation of regional [4] and short to long distance aircraft such as the CeLiner [5][6][7] propulsion technologies suitable for FEA and HEA concepts are discussed and electric air transport appears to offer a promising perspective [6]. Encouraged by a retrofit of an A320, block fuel can be significantly reduced (by 16%) considering a hybrid propulsion concept including a battery [8] Although these researchers differentiate between the power and the energy delivered by the electrical system, a propulsion operation strategy is missing.…”

Optimality considerations for propulsive fuselage power savings

“…Proposed PFC aircraft configurations include NASA's 'FuseFan' concept, 11 the EADS/AGI 'VoltAir', 12 the Boeing 'SUGAR Freeze' 13 and the NASA 'STARC-ABL'. 14 Within the EU-FP7 project 'DisPURSAL', 15 a first multidisciplinary design study of PFC systems layout for large transport category aircraft was performed. During the ongoing EU-H2020 project 'CENTRELINE', the PFC proofof-concept and initial experimental validation is pursued.…”

Performance bookkeeping for aircraft configurations with fuselage wake-filling propulsion integration

“…Mechanical energy outflow rate η ov (-) Overall efficiency η P (-) Propulsive efficiency η th (-) Thermal efficiency θ (m 2 ) Wake momentum area ρ (kg/m 3…”

“…Furthermore, the integration of a single fuselage propulsor on a conventional tube and wing aircraft is potentially feasible in the near future. Exemplary aircraft configurations include the boundary layer ingesting aft fuselage fan concept "Fuse Fan" by NASA [1], the Bauhaus Luftfahrt "Propulsive Fuselage" [2], the propulsive fuselage concepts investigated in the projects "DisPURSAL" [3] and "CENTRELINE" [4], the EADS/ AGI "VoltAir" [5], the Boeing "SUGAR Freeze" [6], NASA "STARC-ABL" [7,8], and the embedded BLI configurations "SAX-40" [9], "Claire Liner" [10], "D8" [11] and the "N3-X" (BWB) [12].…”

“…The propulsive efficiency defined by Smith is denoted as incompressible ( in ) to distinguish it from the following definition by Plas et al3 Assume that β approaches 0 for full boundary layer ingestion and H * approaches 1 for a specific boundary layer profile shape, then η p → 2.…”