分布式推进关键参数对BWB飞机气动特性影响

基于350座级分布式推进系统与翼身融合(BWB)耦合的飞机气动布局设计方案,采用数值计算流体动力学的方法研究了推进系统关键设计参数对飞机气动特性的影响.结果表明:巡航时,推进系统沿机身布置越靠前,质量流量率(MFR)对飞机的气动特性影响越明显,增大MFR在一定范围内提高了飞机的气动效率;进气道入口位置后移可有效提高飞机巡航升阻比,但推进系统进气均匀性的恶化将不利于其有效运行,需权衡考虑;只有选择合适的进气道入口高度才可实现在保持较好的进气条件下提高飞机的气动效率.起飞时,增大MFR可有效提高飞机的起飞升力,与无分布式推进系统的飞机相比,升力最大能提高约20%.

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

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.