Development and Test of AFT-Fuselage BLI Propulsor Experiment

Aircraft boundary-layer ingestion (BLI) propulsion involves a deep mutual aerodynamic interaction between the embedded engines and the airframe. This paper presents wind-tunnel tests followed by numerical validation investigating the aerodynamic characteristics of a representative airframe model with tail-cone BLI propulsor. Starting from a reference fuselage and by means of several axisymmetric optimizations aimed at maximizing the ratio between the net force thrust power to BLI fan disk power, an optimized upswept fuselage geometry with a nonaxisymmetric aft nacelle are derived. The model is manufactured and tested in the Aircraft Research Association transonic wind-tunnel facility at Mach numbers from 0.20 to 0.80, measuring extensive flow data. A detailed computational fluid dynamics study is conducted to assess the ability of steady Reynolds-averaged Navier–Stokes solutions to replicate experimental data. Five grid resolutions for two topologies with three turbulence models are tested at low- and high-speed conditions. The computational fluid dynamics is generally able to reproduce with good accuracy the measured flowfield at the aerodynamic interface plane using a sufficient mesh resolution, with a higher sensitivity to the turbulence closures in areas affected by shear layers and flow separations.