Overall Design and Assessment of Aircraft Concepts with Boundary Layer Ingesting Engines

The assessment of a kerosene driven aircraft concept with a boundary layer ingesting propulsion (BLI) system is content of this paper. The objective is to determine the potential of this BLI technology for short/medium range single aisle aircraft. For this an overall aircraft design (OAD) interpretation of a current Airbus A320neo, called D165, is chosen to be the reference to calibrate the design and assessment methodology. However, the final technology integration results are compared to the Baseline D165-2035 assuming technology level maturation for 2035. This D165-2035 aircraft is equipped with two geared turbofan engines with an increased bypass-ratio of 15.3 at take-off condition. To evaluate the various phenomena driving the aircraft performance and to isolate the impact of the integration of the BLI propulsion system, two intermediate aircraft with rear-mounted engines have been designed. The first one features structurally and flight performance driven positioned rear engines at the location of the rear pressure bulkhead and the second one takes additional constraints into account considering the possibility of burying the engines into the fuselage at the next step without any interaction with the passenger cabin and hence the bulkhead. Finally the BLI configuration D165-2035-TB including two partially buried engines at the rear of the fuselage and a T-tail empennage is investigated and assessed. Besides the investigation of this specific configuration a general overview and further performance improvement potentials of aircraft with boundary layer ingesting propulsion systems are demonstrated and their feasibility is discussed in this paper.