声学风洞风扇段流场特性数值模拟

Numerical study on characteristics of aero-acoustics pilot wind tunnel fan section

关键词:  风洞  风扇  数值仿真  气动性能  噪声  优化设计

Key words:  Wind tunnel  Fan  Numerical simulation  Performance  Noise  Optimized design

摘要:

风扇段是声学风洞的核心部段之一,风扇气动性能和声学性能对风洞的能耗与试验段背景噪声有重要影响。为了获得静叶构型的优化设计参数,采用数值模拟方法,对0.55m×0.4m低湍流度航空声学风洞风扇段的流场特性进行了研究,根据叶片的流动现象,分析了风扇段内部的工作形态,并将其性能与试验数据进行了对比,结果证明该方法能对风扇段性能进行较为准确的模拟。采用该方法得到了动静叶间距、静叶后掠、静叶倾斜对风扇气动性能、流场形态和噪声的影响,静叶后掠对气动性能的影响较小,有助于减小出口的旋转速度,增大动静叶间距对气动性能的影响较大,会增大出口的旋转速度,而静叶倾斜是最适宜的降噪方式。

Abstract:

Fan is one of the core parts of the aero-acoustics wind tunnel section.Performance of the fan including aerodynamic efficiency and acoustics noise has a major impact on the wind tunnel energy consumption and background noise of the test section.To obtain the optimization design parameters of the stator,details of the result were given about characteristics of fan section in 0.55m×0.4m low turbulence aero-acoustics wind tunnel by numerical simulation.Conclusion could be made that numerical methods used could give rational results by comparing with experiment data.Based on flow around rotor and stator,the flow mechanism inside fan section was analyzed.Different fan models were studied based on the numerical results.These parameters imposed influence on performance and flow mechanism of fan including the distance between rotor and stator,stator swept and leaned.Stator swept has little influence on pressure rise of fan section,and can minish tangential velocity at exit.Stator leaned significantly reduces or eliminates rotor wake and tip separation,and can produce a more uniform velocity profile at exit.Conclusions state the importance and feasibility of CFD in aero dynamical design of fan section in wind tunnel.