不同形状涵道风扇推进特性数值分析

以分布式涵道风扇推进为背景，使用多重参考系（MRF）和给定力分布的动量源方法（MSM）求解雷诺平均N-S（RANS）方程，对不同形状涵道风扇推进特性进行了数值模拟分析。对桨盘与不同形状涵道壁面之间的相互作用原理进行了研究，进而对不同外形分布式涵道风扇进行了分析。结果表明:纯圆形机匣推进特性最佳，纯方形最差，由方转圆的机匣推进特性居中；非圆机匣圆角的存在会诱使机匣内壁出现分离，产生干扰阻力，且圆角半径越小，影响越显著；非圆机匣影响风扇进口面积和桨尖涡的大小,从而从桨盘效率和唇口吸力两方面影响涵道推进效率。 

Numerical analysis for propulsion characteristics of ducted fans in different shapes

With distributed ducted fans propulsion as the background, the Reynolds-averaged Navier-Stokes （RANS） equation was solved by using multiple reference frame （MRF） and momentum source method （MSM） with given force distribution, and numerical simulation analysis of ducted fans with different shapes was carried out. The interaction between the fan panel and the duct wall with different shapes was analyzed and compared. Then numerical calculation of distributed ducted fans with different shapes was carried out. It showed that the circle ducted fan had the best propulsion characteristics, while the square ducted fan had the worst. The propulsion characteristics of the rectangular to circular ducted fan was between them. The existence of corners in non-circular ducted fan could induce separation of the inner flow and generate interference resistance, and the smaller radius of the corner indicated the more significant influence. The non-circular duct wall affected the fan inlet area and the size of the blade tip vortex. Therefore, the ducted fan propulsion efficiency was affected via the fan panel efficiency and lip suction.