径向总压畸变对风扇前后流场的影响研究

摘要

采用数值模拟的方法,对某大涵道比小型涡扇发动机的风扇部分进行建模,并分别设置等效低压区为扇形角度60°、90°、120°及150°这4种不同程度的总压畸变进口条件,研究进气道径向总压畸变进口条件下,风扇前后流场的变换规律.研究发现,风扇后流场的总压畸变指数比风扇前大,说明风扇后流场受到风扇转动作用,其不稳定度程度比风扇前大;相对于切向速度和轴向速度,径向速度畸变指数受总压畸变的影响更大;总压畸变指数在风扇前呈增长趋势,且不同径向总压畸变进口条件的变化规律十分相似,总压畸变指数在风扇后存在最大值区域.%Modelling and simulation are used to study a small turbofan engine with high bypass ratio.With four situations of inlet total pressure distortion of equivalent surface of sector angles 60°,90°,120°and 150°,the influence of inlet radial total pressure distortion on forward and backward fan flow of turbofan engine is studied.It is found that the total pressure distortion index is bigger for backward fan part,and it is proved that the unstable level of backward fan part is bigger than forward fan part because of fan rotation;compared with tangential speed and axial speed,the radial speed distortion support is influenced more by inlet radial total pressure distortion;for the flow field of forward fan part,the total pressure distortion has the same type of increase for the four different inlet situations,but it is not the same for backward fan part which has the biggest value area.