双涵道S形弯管气动性能的数值研究

环型双涵道S形弯管是涡轮风扇发动机中连接风扇和高压压气机的重要部件。采用有限容积法对双涵道S形弯管在不同进气条件下的流场进行了数值研究。计算过程中使用两种不同的湍流模型：标准k-ε模型和雷诺应力模型。通过对比可以发现两种湍流模型的计算结果有着明显的差别,尤其是在存在较强剪切应力的区域。此外,还对不同的进气条件（环形管流和均匀来流）对S弯管流场的影响进行了分析。可以看出,不同进气条件中附面层速度剖面的不同能够影响S弯管中轴向速度的分布与发展。

Numerical investigation of the aerodynamic performance of a twin-branch S-shaped duct

An annular twin-branch S-shaped duct is an important component connecting fan and HP compressor in a turbo-fan engine.This paper introduces the numerical investigation of the flow field of a twin-branch S-shaped duct under different inlet conditions with finite volume method.Two different turbulence models-standard k-ε model and Reynolds stress model-are utilized during the computational work.By comparing numerical results of the two different turbulence models,significant variation can be found,especially at the region with relatively strong shear stresses.Additionally,the effect of different inlet conditions（pipe flow and uniform flow inlet condition）on the flow field of S-shaped duct has been analyzed.It can be found that various velocity profiles in the boundary layer under different inlet conditions influence the axial velocity distribution and development of the S-shaped duct.