分布式涵道风扇喷流对后置机翼的气动性能影响

以分布式电推进（DEP）垂直起降（VTOL）无人机（UAVs）为研究背景，采用基于混合网格技术及k-ω SST湍流模型求解雷诺平均Navier-Stokes （RANS）方程的多重参考系（MRF）/动量源方法（MSM），对分布式涵道风扇-机翼构型的喷流气动特性进行了高精度准定常的数值模拟。通过对涵道单元/涵道-机翼的实验验证了零来流条件下数值计算方法的可靠性和高效性，进而对分布式涵道风扇-机翼构型的气动优势进行了分析讨论，最后对分布式涵道风扇的转速、间距、涵道风扇旋转方向等因素进行了数值模拟。研究表明：相比于单个涵道风扇，分布式涵道风扇通过喷流的耦合作用大大提升了机翼的气动特性；分布式涵道风扇不同转速的喷流对截面翼型的压力分布和周围流场的速度分布影响具有一定的相似性，但具体数值随转速变化；分布式涵道风扇间距的增大会改善涵道风扇单元的拉力特性，机翼的气动特性会随之降低；涵道风扇合理的旋转方向不仅会使得下翼面喷流区域的高压过渡更加平缓，静压数值更加连续，而且内侧涵道风扇也会被外侧喷流所激励，对机翼的升力特性产生更好的诱导效果。

Effects of distributed electric propulsion jet on aerodynamic performance of rear wing

Based on the research of the Vertical Take-Off and Landing (VTOL) Unmanned Aerial Vehicles (UAVs) with Distributed Electric Propulsion (DEP), high-precision quasi-steady numerical simulation of the jet flow aerodynamic effects of different DEP-wing configurations are conducted using the Reynolds-Averaged Navier-Stokes (RANS) equations of the Multiple Reference Frame (MRF)/Momentum Source Method (MSM) based on the hybrid grid technology and k-ω SST turbulence model. The reliability and efficiency of the numerical method under the zero-velocity freestream condition are verified by the experiment of solo ducted fan/ducted fan and wing configurations. The aerodynamic advantages of the DEP-wing configuration are then analyzed. Finally, the rotating speed, spacing of the DEP and the rotating direction of the ducted fan are numerically simulated. Results show that the aerodynamic characteristics of the wing are significantly improved by the jet coupling effect of the DEP, compared with the solo ducted fan; the aerodynamic characteristics of the wing are similar at different rotating speeds of the DEP; the dynamic characteristics of the ducted fan will be improved with the increase of the spacing of the DEP, while those of the wing will be reduced; the reasonable rotation direction of the ducted fan enables smoother high pressure transition in the lower wing jet area and more continuous static pressure values; in addition, the inner ducted fan is motivated by the side jet flow, producing a better induction effect on the lift characteristics of the wing.