Proof of Concept Study for Fuselage Boundary Layer Ingesting Propulsion

Abstract

Key results from the EU H2020 project CENTRELINE are presented. The research activities undertaken to demonstrate the proof of concept (technology readiness level—TRL 3) for the so-called propulsive fuselage concept (PFC) for fuselage wake-filling propulsion integration are discussed. The technology application case in the wide-body market segment is motivated. The developed performance bookkeeping scheme for fuselage boundary layer ingestion (BLI) propulsion integration is reviewed. The results of the 2D aerodynamic shape optimization for the bare PFC configuration are presented. Key findings from the high-fidelity aero-numerical simulation and aerodynamic validation testing, i.e., the overall aircraft wind tunnel and the BLI fan rig test campaigns, are discussed. The design results for the architectural concept, systems integration and electric machinery pre-design for the fuselage fan turbo-electric power train are summarized. The design and performance implications on the main power plants are analyzed. Conceptual design solutions for the mechanical and aero-structural integration of the BLI propulsive device are introduced. Key heuristics deduced for PFC conceptual aircraft design are presented. Assessments of fuel burn, NOx emissions, and noise are presented for the PFC aircraft and benchmarked against advanced conventional technology for an entry-into-service in 2035. The PFC design mission fuel benefit based on 2D optimized PFC aero-shaping is 4.7%.

Development of a Multi-Segment Parallel Compressor Model for a Boundary Layer Ingesting Fuselage Fan Stage

“…Furthermore, the same thrust can be archived with smaller engines and nacelles, leading to further weight and drag reduction, in turn smaller required wing area and, therefore, again reduced weight and drag [6,9]. BLI can also be seen as an alternative way to achieve a very low specific thrust without the sizing related challenges that arise from conventional propulsor designs with increasing bypass ratio and nacelle diameter [10].…”

“…This neglects the effect of the T-tail empennage on the inflow conditions and does not consider cross wind conditions or effects from the aircraft angle of attack. According to [10], for commercial transport aircraft, 60% to 70% of drag is of viscous nature. The fuselage is of particular interest for wake filling BLI propulsion because it induces almost half of that portion.…”

“…The advantage of a fuselage engine configuration is thus, that high amounts of boundary layer can be ingested with an rotationally symmetric distortion pattern, making an adapted fan design possible do minimize boundary layer induced aerodynamic losses while significantly increasing the propulsive efficiency. Fuselage tail engine concepts are, therefore, subject to various other ongoing research projects, most notably the NASA "STARC-ABL" project, see e.g., [2,14], as well as the Bauhaus Luftfahrt e. V. project "CEN-TRELINE", e.g., [10].…”

Non-axisymmetric complete flow conditioning gauzes

“…The proposed gauze technology has been applied to replicate the flow distortion at the inlet of a BLI fan. The fan of interest is located at the aft-section of CENTRELINE's propulsive fuselage concept (Seitz et al 2021). This aircraft configuration includes a cylindrical fuselage, wings, belly fairing and a vertical tail place upstream of the fan (Fig.…”

Special Issue “10th EASN International Conference on Innovation in Aviation & Space to the Satisfaction of the European Citizens”

“…The results show that under an emissions point of view blended fuels can be used to fuel gas turbines. Seitz et al [7] present key results for the EU H2020 project CENTRELINE, undertaken to demonstrate a proof of concept for the so-called propulsive fuselage concept (PFC) with boundary layer ingestion (BLI). A performance bookkeeping scheme for the BLI propulsion is reviewed and findings from the high-fidelity aero-numerical simulation and aerodynamic validation testing in wind tunnel and BLI fan rig test campaigns are discussed.…”