弯掠动叶旋转失速工况下气动声学的实验分析与计算

Experiment and Calculation on Aeroacoustic Performance of Skewed-Swept Rotor Blades

测量了轴流式弯掠动叶和径向动叶在旋转失速工况下的气动噪声和噪声频谱，实验结果表明：弯掠动叶能够降低气动噪声。讨论了弯掠动叶对宽频噪声和离散噪声的影响，并且得到了适于计算弯掠动叶旋转失速工况的气动噪声计算方法。

The experiments on aeroacoustic performance of axial fans with radial (conventional) and skewed-swept rotor blades are carried out on the condition of same peak pressure rise and flow rate. Two prototype fans are designed with same geometrical and aerodynamic parameters. One is a baseline fan with blades stocking line radically oriented, and the other is fan having 8. 3°forward skewed-swept angle. Aerodynamic noise and noise frequency spectrum on skewed-swept rotor blades are measured in rotating stall. Noise was reduced about 3-4 dB(A) overall. Influence of skewed- swept rotor blades on broad- band sound power level and discreting sound power level is discussed. Five calculation methods of aeroacoustic property are analyzed, and one calculation noise-method is select ed and applied to skewed-swept rotating stall condition, the calculation noise results are obtained in close agreement with experiment noise data.