Propulsion installation characteristics for turbofan transports

Several investigations have been conducted in the Langley 8-Foot Transonic Pressure Tunnel and the Langley 16-Foot Transonic Tunnel to investigate propulsion integration characteristics for turbofan transport aircraft. These studies have focused on reducing the interference drag for conventional underwing, overwing, upper surface and wing aft-mounted engine nacelle installations. The experimental data presented in this paper will illustrate the difficulties associated with properly integrating nacelles and pylons with advanced supercritical wings. In addition guidelines for integrating the nacelle/pylons to eliminate adverse interference effects and possibly achieve favorable interference are discussed.