Conceptual investigation of a propulsive fuselage aircraft layout

Abstract

Purpose -The purpose of this paper is the multi-disciplinary conceptual investigation of a propulsive fuselage (PF) aircraft layout allowing for new performance synergies through closely coupled propulsion/airframe integration. The discussed aircraft layout facilitates the ingestion of the fuselage boundary layer and the utilization of wake filling, thus eliminating a significant share of fuselage drag. Design/methodology/approach -Based on consistent book-keeping standards for conventionally installed and highly integrated propulsion systems, key aspects of conceptualisation regarding airframe and propulsion system are presented. As a result of this, a PF aircraft configuration is proposed featuring a fuselage fan power plant in conjunction with two under-wing podded power plants. Parametric models for integrated aircraft and propulsion system sizing and performance analysis are discussed that are suitable for the consistent mapping of the characteristics intrinsic to a PF layout. In an initial benchmarking exercise, the vehicular efficiency potentials of the previously identified PF configuration are evaluated against an advanced conventional reference aircraft. Findings -During benchmarking, it was found that a best and balanced design for the proposed PF aircraft layout yields an increase in vehicular efficiency of approximately 10 per cent compared to the advanced conventional reference aircraft. Practical implications -The paper gives the reader an idea for the efficiency potentials achievable through a PF aircraft configuration, as well as guidelines for aircraft sizing and integrational aspects. It may serve as a basis for advanced studies in the future. Originality/value -The conceptual investigation of the PF concept idea, contributes to establishing the initial technical feasibility of this novel approach to synergistic propulsion system integration. The methods presented in this paper allow for the multi-disciplinary conceptual design sizing of a PF aircraft.

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

“…intake additive drag, nozzle discharge and exhaust shear flow, conformed to the convention presented in Section 3.2.1. As air entering propulsive device inlets necessitated the prediction of appropriate ram recovery factors for purposes of adjusting power plant performance analysis, in the first instance, constant degradation factors were applied to fan efficiency as described by Seitz et al (34) . A subsequent refinement in predicting penalising aspects to pressure recovery were derived from the multi-disciplinary numerical aero-experimental activities, as described in Section 3.2.2.…”

“…A matching procedure to incorporate physical effects derived from the aero-numerical analysis was undertaken such that consistency between the GasTurb® models and CFD results were secured. Regression models were derived for important working parametres such as the intake pressure ratio, and a review of such methods can be found in publications produced by Bijewitz et al (35) , Seitz et al (34) and Seitz and Gologan (29) . Since the 0D GasTurb® plus in-house engine performance software used in the DisPURSAL Project did not have a built-in functionality to account for the impact of inlet flow radial distortions on fan efficiency and surge margin, the Parallel Compressor Theory (PCT) method (32) mainly concerned with circumferential distortion was incorporated.…”

Installed Performance Assessment of a Boundary Layer Ingesting Distributed Propulsion System at Design Point

“…The boundary layer is an inherently distorted flow, which will almost certainly have some impact on the performance of the system. The engine may be subject to distorted flow from the bottom to the top of the inlet, or radially along the fan blade, such as in the case of a propulsive fuselage [6]. Significant distortion can negate the power or fuel consumption benefits of a BLI system, such that a free-stream system is the more efficient option [5].…”

“…Similarly, the Silent Aircraft Initiative's SAX-40 makes use of three boundary layer ingesting engine clusters [11] which ingest 16.6% of the airframe boundary layer [5]. On conventional tube-and-wing configurations an aft mounted BLI propulsion system in the tail section of the airframe may be used to re-energise the fuselage wake [6,12].…”

Electric Drives for Propulsion System of Transport Aircraft

“…This is mainly the reason why distributed propulsion has been intensively investigated on Blended Wing Body (BWB) configuration [12,48] as it offers large potential for application of BLI by distributing buried propulsion devices along the trailing-edge of the fuselage (see Section 3). For BLI application on tube and wing configurations, the Propulsive Fuselage configuration, which is characterized by a large fan encircling the rear end of the fuselage, was evaluated as most promising and was the center of several investigations [49][50][51][52][53].…”