Modeling of Jet-by-Jet Diffraction
Modeling of Jet-by-Jet Diffraction
复制标题
逐射流衍射建模
DOI：
10.2514/6.2013-614
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发表时间：
2013
影响因子：
3.5
通讯作者：
D. Papamoschou
中科院分区：
文献类型：
--
作者：
D. Papamoschou
本文提出了一种预测逐喷流衍射的分析模型。源射流被建模为辐射圆柱体，在其上可以规定任意的压力分布。这种处理方法使波包源，成为突出的喷气噪声的模拟纳入。散射射流被模拟为具有可变马赫数和温度的活塞流的无粘圆柱界面。环境马赫数也是可变的。该分析解决了入射场、散射场和透射场的对流波方程。为了与现有的实验进行比较，辐射圆柱上的规定的压力场被参数化，以再现孤立射流的远场强度的实验方向性。结果表明，由射流的流体界面的散射是一个强大的现象，类似于从一个固体圆柱体的散射的量级。确定了衰减和放大区域。与现有的实验数据的比较表明，该模型预测的减少和放大的趋势具有良好的协议，其保真度优于过去的模型，使用点源来模拟喷气噪声。
The paper presents an analytical model for the prediction of jet-by-jet diffraction. The source jet is modeled as a radiating cylinder on which one can prescribe an arbitrary pressure distribution. This treatment enables the incorporation of wavepacket sources that are becoming prominent in the simulation of jet noise. The scattering jet is modeled as an inviscid cylindrical interface with plug flow of variable Mach number and temperature. The ambient Mach number is also variable. The analysis solves the convective wave equation for the incident, scattered, and transmitted fields. To compare with available experiments the prescribed pressure field on the radiating cylinder is parameterized to reproduce the experimental directivity of the far-field intensity of the isolated jet. The results show that scattering by the fluid interface of the jet is a powerful phenomenon of similar magnitude as scattering from a solid cylinder. Regions of attenuation and amplification are identified. Comparison with available experimental data indicates that the model predicts the reduction and amplification trends with good agreement, its fidelity being better than those of past models that used a point source to simulate the jet noise.