串列式扇翼布局流动特性数值研究

扇翼能够通过前缘横流风扇的高速旋转对前方来流进行加速和重新整流。利用这一特点提出了一种串列式扇翼布局，其由一定间距和空间高度分布的前后双排或多排扇翼组成，并基于二维模型对该布局开展了流动数值模拟，分析得到了不同前后间距、高度差以及排数下串列式扇翼布局的升力和推力特性。结果表明，相对单个扇翼，在合适的设计参数下串列式扇翼可得到更大的单排平均升力和推力，其中间距一倍风扇直径的四排扇翼平均升力和推力分别提高了约10%和30%。基于扇翼附近流场分布和翼型上下表面压强分布，分析了引起升力和推力提升的原因。该研究可为未来设计具有更好低速大载荷特性的扇翼飞行器提供参考。

Numerical investigation into flow characteristics of tandem fan-wing configuration

Fan-wing can accelerate and rectify the air inflow through the rapid rotation of crow flow fan in the leading edge. Taking advantage of this distinguishing feature, a tandem fan-wing configuration is put forward, which is composed by double or multiple rows of fan-wings arranged in tandem with certain spacing and spatial distribution. The flow characteristics of the tandem fan-wing configuration are simulated based on two dimensional models, and the lift and thrust loads are calculated for different spacing, height disparities and row numbers. Results indicate that compared to single fan-wing, larger lift and thrust can be obtained by properly designed tandem fan-wing configuration. For instance, the four-row fan-wing with uniform spacing of one fan diameter possesses larger average lift and thrust by about 10% and 30%,respectively. The reason accounting for the improvement of lift and thrust is analyzed based on the flow filed near the fan-wings and the pressure distribution over the airfoils. These investigations can provide useful guidance for the design of future fan-wing aircraft with better low-speed large-load characteristics.