Characterization and suppression of the hydrodynamic instability in the time domain for acoustic propagation in a lined flow duct
Characterization and suppression of the hydrodynamic instability in the time domain for acoustic propagation in a lined flow duct
复制标题
内衬流道中声传播时域流体动力学不稳定性的表征和抑制
DOI：
10.1016/j.jsv.2021.115999
复制
发表时间：
2021
影响因子：
4.7
通讯作者：
M. Galland
中科院分区：
文献类型：
--
作者：
Yuanyuan Deng;Antoni Alomar;D. Dragna;M. Galland
评估了梯度项抑制（GTS）方法，用于消除线性化欧拉方程（LEE）沿衬里流道的时域解中出现的流体动力学不稳定性。为此，首先借助补充模态分析来描述时域对流不稳定性的特征。研究了网格尺寸和空间滤波对不稳定性的影响。特别是，对于足够小的网格尺寸，实现了时域不稳定性的收敛。然后研究抑制模式上的平均流量梯度项的结果。结果表明，不稳定模式确实被消除了，但声学模式也被显着修改，特别是对于低亥姆霍兹数。 GTS方法最终应用于NASA掠射阻抗管基准测试。研究发现，调整 LEE 内平均流梯度项的权重可以有效抑制不稳定性，同时保持声学分量的合理精度。
The gradient term suppression (GTS) method for removing the hydrodynamic instability appearing in the time-domain solutions of the linearized Euler equations (LEE) along a lined flow duct is assessed. For this, the characterization of a convective instability in the time domain, with the aid of a complementary modal analysis, is first presented. The effect of the mesh size and spatial filtering on the instability is investigated. In particular, a convergence of the instability in the time domain is achieved for a small enough grid size. The consequence of suppressing the mean flow gradient term on the modes is then investigated. It is shown that the unstable modes are indeed removed, but also that acoustic modes are significantly modified, especially for low Helmholtz numbers. The GTS method is finally applied to the NASA grazing impedance tube benchmark. It is found that tuning the weight of the mean flow gradient term within the LEE can be effective for suppressing the instability while conserving a reasonable accuracy of the acoustic component.