Spectral broadening of jet engine turbine tones
Spectral broadening of jet engine turbine tones
复制标题
喷气发动机涡轮音的光谱展宽
DOI：
10.2514/6.2008-2940
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Marco Rose
中科院分区：
文献类型：
--
作者：
R. Ewert;O. Kornow;C. Powles;B. Tester;J. Delfs;Marco Rose
湍流散射的过程进行了研究的一般实验Candel等。1应用分析弱散射模型和CAA计算。对于解析弱散射模型，使用Lilley方程的近似形式。该方程的源项是湍流和入射声场的项。在CAA模拟中，Pierce提出的声波在非定常非均匀流中的波动方程被集成。非定常湍流基流采用随机方法模拟，以产生具有时均RANS提供的局部变化湍流特征的湍流。为了研究频谱展宽效应的分析和计算，Candel的实验装置被认为是，其中包括一个全向声源，位于轴上的圆形射流。分析预测显示，对于垂直于喷流轴的观察者位置，坎德尔测量的总体趋势非常一致。计算揭示了光谱形状，这是在良好的协议与实验中发现的。
The process of turbulent scattering is studied for the generic experiment conducted by Candel et al.1 applying an analytic weak scattering model and CAA computations. For the analytic weak scattering model an approximate form of the Lilley equation is used. The source terms of this equation are in terms of the turbulence and the incident acoustic field. In the CAA simulations the wave equation proposed by Pierce for sound in fluids with unsteady inhomogeneous flow is integrated. The unsteady turbulent base-flow is modeled using a stochastic method to generate turbulence with locally varying turbulence features as provided by time-averaged RANS. To study the spectral broadening effect analytically and computationally, the experimental set-up of Candel is considered, which involves an omnidirectional sound source, located on the axis of a round jet. The analytical predictions show very good agreement with the general trends as measured by Candel for an observer position normal to the jet axis. The computations reveal a spectral shape, which is in good agreement with those found in the experiments.