AI 中文总结
本文通过强耦合高保真PM-FSI模拟，量化了分离气动流中PM的截断共振频率和位移振幅与耦合系统响应参数的定量关系，明确了不同FSI状态的存在，为气动流动控制的PM设计提供了新方法。
AI 中文摘要
具有工程化共振的声子材料（Phononic Materials, PMs）已被用于处理流体-结构相互作用（Fluid-Structure Interaction, FSI）与流体流动不稳定性，取得了转捩延迟、高超声速边界层稳定、气动升力提升等有益成果。此前的PM-FSI研究主要是识别感兴趣的时空流动尺度，并选择能产生利于FSI的结构动力学的PM结构参数。然而，完全耦合的FSI系统通常会产生复杂的耦合动力学，单独研究任一物理系统都无法准确捕捉这些动力学。在此背景下，作者的前期工作在有限参数范围内确定了控制分离气动流中耦合PM-FSI动力学的行为参数。本文采用该框架，在更宽的两个行为参数——截断共振频率和位移振幅——范围内开展强耦合高保真PM-FSI模拟，以建立它们与耦合系统响应中耦合频率、升力和环量之间的定量（线性/三次方）关系。此外，结果表明存在不同的FSI regime（状态），具体取决于截断共振频率或其亚谐波/超谐波与涡脱频率的接近程度。观察到的FSI动力学包括多频/单频动力学、因流体附加质量效应导致的耦合频率下移、非线性谐波的产生，以及FSI动力学收敛到刚性平板情况。这些结果重申了PM频率和振幅在确定耦合FSI动力学方面的重要性，所提出的定量关系为设计用于气动流动控制以实现升力提升等有益效果的PM提供了新途径。
英文摘要
Phononic materials (PMs) with engineered resonances have been leveraged for fluid-structure interaction (FSI) with fluid flow instabilities, yielding beneficial outcomes such as transition delay, stabilized hypersonic boundary layers, and increased aerodynamic lift. Prior PM-FSI studies primarily identify spatio-temporal flow scales of interest and choose PM structural parameters producing structural dynamics conducive for FSI. However, a fully-coupled FSI system generally produces complex coupled dynamics that is not accurately captured by studying either physical system in isolation. In this context, our prior work established behavioral parameters that govern the coupled PM-FSI dynamics in a separated aerodynamic flow over a limited parameter range. Adopting this framework, this paper explores strongly-coupled high-fidelity PM-FSI simulations over a broader range of two behavioral parameters---truncation resonance frequency and displacement amplitude---to establish their quantitative (linear/cubic) relations to the coupled frequency, lift force, and circulation in the coupled system response. In addition, the results indicate the presence of distinct FSI regimes, depending on the proximity of the truncation resonance frequency or its sub-/super-harmonics to the vortex-shedding frequency. FSI dynamics ranging from multi-/single-frequency dynamics, downshifted coupling frequency due to fluid-added mass effects, generation of non-linear harmonics to convergence of FSI dynamics to the rigid plate case are observed. These results reiterate the importance of the PM frequency and amplitude in determining the coupled FSI dynamics, and the proposed quantitative relations provide a new pathway for designing PMs for aerodynamic flow control to achieve beneficial outcomes, e.g., lift force enhancement.
Comments23 pages, 6 figures
