Integration of an Inner Mixing Aft-Mounted Engine Concept in a Research Configuration with Boundary Layer Ingestion

Abstract

The Collaborative Research Centre (CRC) TRR 364 entitled "Synergies of Highly Integrated Transport Aircraft" is set-up to address the synergetic utilisation of aircraft components like boundary layer ingestion or distributed propulsion. Its main goal is to investigate potentials of highly integrated aircraft concepts by in-depth cross-system analysis. The following paper describes the generation of an aerodynamic configuration with rear-fuselage mounted boundary layer ingestion engines with ultra high bypass ratio. The TLARs of the configuration are similar to those of an A320neo. The aircraft concept is one out of three investigated in the CRC 364. It is designated as "Configuration 1a". The main focus lies on the engine integration and the deduction of a viable reference aircraft geometry suitable for high fidelity aerodynamic research. In a first step, the aircraft geometry which is provided by the preliminary design sub-project of SynTrac, has to be modified by incorporating suitable airfoils and configuration clean-ups in order to reduce areas with flow separations occurring on various parts on the configuration. In a second step, the integration of the BLI engine is carried out, identifying a suitable engine location, degree of embedding and attitude. A first design of the inlet area is presented together with fairings for the intersection between nacelle and aft fuselage. Additionally, the intake has been adapted to the mass flow requirements be a widening of 15 \% at an degree of embedding of 49 \%. Finally, the impact of a variation of the engine incidence angles at the specified location is studied.