Industrial distortion index assessment for a boundary layer ingestion engine

Abstract

A possible solution to improve the aircraft efficiency for the next decades is the use of boundary-layer ingestion engines. One of the industrial challenges linked to this type of engines is the aerodynamic distortion at engine intake. This work proposes to evaluate the characterization capability of several distortion indices, currently used in the industry, on a boundary layer ingestion engine configuration. The analysis is performed using several Reynolds-Averaged Navier-Stokes simulations. First, steady simulations of a simplified boundary-layer ingestion air intake are performed for off-design conditions. The principal distortion indices used in the industry are calculated for each flow solution. The results are discussed to assess their potential to highlight physical phenomena present in this configuration. Finally, this analysis allows identifying the weaknesses of the current distortion indices and to propose ways of improvement for new distortion indices more adequate for boundary layer ingestion configurations.