尾迹/势流干扰对跨声速风扇静叶附面层流动影响的数值研究

Numerical Investigation of Wake/Potential-Stator Boundary Layer Interaction in a Transonic Fan Stage

关键词:  非定常干扰  附面层转捩  尾迹  压气机

Key words:  Unsteady interaction  Boundary layer transition  Wake  Compressor

摘要:

为揭示尾迹/势流干扰下压气机静叶附面层的非定常流动机理，采用数值方法对单级高负荷跨声速风扇中径处的非定常流场进行模拟，针对尾迹/势流干扰下的静叶附面层非定常流动特征进行研究。基于尾迹/势流与叶片附面层干扰模型，通过叶片壁面摩擦力、近壁面附面层湍动能和壁面静压脉动，详细分析了尾迹和势流干扰下尾迹对高负荷静叶附面层流动状态的影响。研究发现:在非定常条件下，尾迹干扰能够“刺穿”静叶附面层，使得静叶附面层发生跨越转捩现象。尾迹和受其诱导的势流碰撞静叶前缘产生的压力扰动波在压力面附面层内以声速传播，影响压力面整个弦长的静压和摩擦力分布，而在吸力面上，扰动波的传播仅局限在前缘区域部分弦长上，吸力面和压力面传播现象不同与逆压梯度和曲面凸、凹形状相关。

Abstract:

In order to reveal the unsteady flow mechanism of compressor blade boundary layer under rotor/stator aerodynamic interaction，numerical simulation was applied to investigate the unsteady boundary layer flow of the stator at the mid-span in a high loading transonic fan stage. Critical parameters，including skin friction，turbulence kinetic energy and static pressure fluctuation on the blade surface，were analyzed in detail to describe the unsteady effects of the high loaded stator boundary layer based on the model of rotor wake/potential-stator boundary layer interaction. The numerical results show that the bypass transition would occur in the stator boundary layer during the impinging of the rotor wake. And also，a pressure fluctuation would propagate with the speed of sound along the blade boundary layer after the leading edge was impinged by the wake. The distribution of the pressure and friction along the whole pressure side and the leading edge of the suction side were affected by the pressure fluctuation propagation. The pressure fluctuation effect was determined by the pressure gradient and the blade surface shape.