静叶时序对压气机叶片附面层流动影响的数值研究

采用数值方法对两级低速压气机中径处的非定常流场进行模拟,针对压气机第2排静叶两个典型周向位置对动静叶干扰下的叶片附面层流动进行研究.建立尾迹与附面层干扰分析模型,结合叶片壁面摩擦力和近壁面附面层湍动能,详细分析了尾迹和势流干扰下静叶时序改变对叶片附面层流动产生的影响.对第2排静叶附面层的研究结果表明:静叶时序改变了尾迹在其叶排中的输运特征,能够降低壁面摩擦力和近壁面湍动能及其非定常最大波动幅值,影响吸力面附面层内动叶尾迹后沉寂区的宽度.在非定常条件下,尾迹能够诱导静叶层流附面层在尾迹干扰的局部范围内转捩发展为湍流状态,同时高湍流度尾迹的干扰具有抑制逆压梯度下附面层分离的作用,并能够延长层流区的范围.

Numerical Investigation of the Effect of Stator Clocking on Blade Boundary Layer Flow in Compressor

Numerical simulation is applied to investigate the unsteady flow fields at the mid-span of a two-stage low-speed compressor. Detailed analysis of blade unsteady boundary layer flow of rotor-stator interaction condition is presented by the analysis model of rotor wake and stator boundary layer interaction under typical clocking positions of the second stator row. The skin friction of suction side and turbulence kinetic energy close to the suction side are presented to analyze the effect of stator clocking on blade boundary layer flow. Results of the research on the second stator boundary layer show that stator clocking alters the transportation character of the wakes in the stator flowfield, reduces the skin friction and turbulence kinetic energy close to the wall as well as the maximum unsteady fluctuations. And it also affects the calmed region width behind the rotor wakes in the stator blade suction side boundary layer. Under unsteady condition, the stator laminar flow can be induced to turbulent flow in local wake disturbance region(wake-induced transition), and the wake disturbance with high turbulence intension is able to control the boundary layer separation flow under negative pressure gradient and to extend the range of laminar region.