In this study the effect of film cooling on entropy wave attenuation and indirect entropy noise generation was investigated in a subsonic stator blade row with a leading-edge, pressure-side, and suction-side cooling geometry. The investigation was conducted on a small blade midspan section (in a linear cascade arrangement), using a three-dimensional unsteady Reynolds-averaged Navier–Stokes simulation approach. A planar entropy wave was injected at the inlet for a range of frequencies from 200 to 1000 Hz. Additionally, the compact model by Cumpsty and Marble was extended to account for a cooling flow. Results show that for an increase in coolant mass flow rate of 3.4%, the entropy noise increases by about 12% for the transmitted pressure wave, whereas the reflected pressure wave increases by about 9%. This is attributed to the change in convective acceleration in the blade passage. The film cooling was found to have a minor effect in promoting the entropy wave attenuation. The extended compact model was capable of capturing both the entropy wave attenuation and increase in the acoustic transfer function due to film cooling.

在这项研究中，研究了在具有前缘，压力侧和吸力侧冷却几何形状的亚音速定子叶片行中，薄膜冷却对熵波衰减和间接熵噪声产生的影响。使用三维非稳态雷诺平均Navier–Stokes模拟方法，在小叶片中跨部分（线性级联排列）上进行了研究。平面熵波在入口处注入，频率范围为200至1000 Hz。此外，Cumpsty and Marble的紧凑型模型得到了扩展，以解决冷却问题。结果表明，当冷却剂质量流量增加3.4％时，传递的压力波的熵噪声增加约12％，而反射的压力波的噪声增加约9％。这归因于叶片通道中对流加速度的变化。发现薄膜冷却对促进熵波衰减的影响较小。扩展的紧凑模型能够捕获由于薄膜冷却而引起的熵波衰减和声学传递函数的增加。