Abstract A dynamic mode decomposition (DMD) is carried out for the flow field in a compressor cascade with plasma actuators employed for aeroelastic control. Numerical assessments performed in previous works have shown that alternate triggering of pressure side/suction side actuators installed at the trailing edge of the blades can effectively reduce vibratory loads and enlarge the flutter boundaries of a linear compressor cascade. With the twofold aim of obtaining an in-depth understanding of the flow physics associated to plasma actuation and ultimately developing an optimized control law for the actuators, the dominant structures of the pressure field are extracted via a dynamic mode decomposition. The decomposition is conducted on the actuated and non-actuated pressure fields at several inter blade phase angles. The fundamental effects of plasma actuations on the flow field, and in turn on the blade loading, are identified and discussed. The procedure allows obtaining an useful picture of the main fluid mechanic phenomena associated to plasma aeroelastic control on turbomachinery blades. Additionally, the DMD spectrum and its coherence are analysed, yielding a wider energetic spread over high-order modes for the plasma-actuated case, in comparison to the clean cascade.

中文翻译：

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级联翼型等离子气弹控制的动态模态分解分析

摘要 对具有用于气动弹性控制的等离子体致动器的压缩机级联中的流场进行了动态模态分解 (DMD)。先前工作中进行的数值评估表明，安装在叶片后缘的压力侧/吸入侧执行器的交替触发可以有效地减少振动载荷并扩大线性压气机叶栅的颤振边界。为了深入了解与等离子体驱动相关的流动物理学，并最终为驱动器开发优化控制法则，压力场的主要结构是通过动态模式分解提取的。分解是在几个叶片间相位角的驱动和非驱动压力场上进行的。确定并讨论了等离子体驱动对流场的基本影响，进而对叶片载荷产生了影响。该程序允许获得与涡轮机械叶片上的等离子体气动弹性控制相关的主要流体力学现象的有用图片。此外，分析了 DMD 光谱及其相干性，与清洁级联相比，在等离子体驱动情况下，在高阶模式上产生了更广泛的能量分布。