Effects of distributed propulsion crucial variables on aerodynamic performance of blended wing body aircraft

Abstract

Based on a 350-passenger blended wing body( BWB) integrated aircraft with a distributed propulsion system,effects of crucial design variables of distributed propulsion on aerodynamic performances of the aircraft are studied by a computational fluid dynamics method. It is shown that the effect of the mass flow rate( MFR) on aerodynamic performance in cruising becomes more obvious when the propulsion system moving forward along the aircraft and the aerodynamic efficiency increases with the increase of MFR as well. With the intake location of the propulsion system moving backward along the aircraft,the lift-to-drag ratio increases,but the non-uniform intake flow also increases which decreases the efficiency of the propulsion system. It needs a trade-off to determine the intake location. The aerodynamic efficiency of the aircraft can also be increased by a suitable intake height of the propulsion system meanwhile maintain a uniform intake flow. The lift can be enhanced by up to 20% with a larger MFR in taking off,compared with the aircraft without distributed propulsion system.