可压升力面理论桨扇气动设计反问题方法

结合桨扇几何与流动特征讨论了其两大类设计方法的特点，研究了基于可压升力面理论的一种桨扇气动设计反问题方法.相比于传统螺旋桨升力面设计方法，其在旋转坐标系中小扰动线性化假设下严格处理了桨叶旋转、流动压缩性、宽弦大后掠桨叶和桨叶间相互作用，体现了桨扇有轮毂而无机匣的特征.给出了桨扇设计中载荷-下洗角、厚度-下洗角核函数表达式，与机翼核函数的对比验证了其准确性，给出了其在升力面弦向积分和展向积分中的处理方式.讨论了反问题中各设计分布参数的给定方式，特别是最佳载荷分布的给定.构造了一种修正反问题设计中流动损失影响的损失模型.给出了设计算例，数值分析了该设计方法的准确性.研究表明，在跨声速区，反问题给定的弦向载荷分布与数值模拟的存在一定差异，这主要由该设计方法线性化假设与跨声速流动非线性的差别造成.反问题得出的基元功率系数分布、总体性能参数与数值模拟的吻合较好. 

Inverse design approach for propfan aerodynamics based on compressible lifting surface theory

Two kinds of design methodologies of propfan were briefly discussed combined with its structure and flow features. Based on the compressible lifting surface theory, an inverse approach for propfan aerodynamics design was developed. Compared with the traditional lifting surface design method of propeller, the effects of blade rotation, compressibility, long chord length, large sweep angle and blade interference were treated strictly under the small distribution linearization assumption in rotating coordinate system. The features of the profan with hub but without casing were reflected. The kernel functions of loading-downwash angle and thickness-downwash angle for propfan design were given. The kernel functions were verified by comparing with the wing kernel functions and their convergences were studied. The chordwise and spanwise integrals of the kernel functions were discussed in detail. The ways of prescribing the distributions of design parameters, especially the optimum loading distribution, were discussed. A loss model to modify the effect of flow loss on inverse design was made. A design example was given and the accuracy of this inverse design approach was analyzed. Studies show, at some transonic sections, the prescribed chordwise loading distributions have some differences from those of numerical simulation of the designed blade due to the linearization assumption differing from the real flow nature. The prescribed element power coefficient distribution and the overall performance agree well with the numerical simulation.