Investigation of the effects of boundary layer ingestion engine integration on aircraft thrust requirement

In order to further the understanding of boundary layer ingestion (BLI) engine integration concepts the DLR project AGATA^3S aimed at modelling and evaluating the inhomogeneous inflow into turbofans positioned on either side of the rear fuselage. Besides investigating increased flow-induced blade vibrations as well as the excitation of additional noise sources, a focus within AGATA^3S was the assessment of BLI on overall aircraft performance. The present paper discusses the results of a parameter study carried out on the DLR TuLam aircraft in which a UHBR engine was embedded into the rear fuselage to varying degrees in order to understand the relationship between degree of embedding and total aircraft thrust requirement. The TuLam underwing-mounted engine configuration was used as a reference. The performance data as well as the phenomenological effects of BLI engine integration are assessed.