Numerical and Experimental Aerodynamic Investigations of Boundary Layer Ingestion for Improving Propulsion Efficiency of Future Air Transport

Abstract

This paper presents the recent investigations of the Boundary Layer Ingestion (BLI) concept conducted at ONERA. Both numerical and experimental investigations of a BLI propulsion system are conducted synergistically with the objectives of preparing and validating both the numerical simulations tools and the experimental methodologies that will be necessary for the design of a future transport aircraft incorporating a BLI propulsive system. A test rig dedicated to the investigation of BLI has been specifically designed manufactured and tested in the ONERA L1 wind tunnel in Lille in low-speed conditions. This experimental rig embeds an electrically powered fan and several measurements capabilities including separate measurements of the forces acting on the different model components, thus allowing a in depth investigations and quantification of the mechanisms of BLI. Numerical simulations of this test rig, based on RANS CFD calculations using the Actuator Disk (AD) approach to model the effect of the fan absorbing a boundary layer flow have been used, first to help defining the experimental test rig and then, using the experimental results to establish and validate a numerical simulation approach which could be used in the future to facilitate the integration of a BLI propulsion system on a future transport aircraft.