Zhang Lucy T, Krane Michael H, Yu Feimi
Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, NY 12180, USA.
Applied Research Laboratory, Pennsylvania State University, PA 16802, USA.
Comput Fluids. 2019 Mar 30;182:108-117. doi: 10.1016/j.compfluid.2019.02.013. Epub 2019 Feb 16.
In this study, an aeroacoustic fluid model for slightly-compressible isentropic flows is developed and evaluated for its compressibility effects in the context of fluid-structure interactions. This model considers computational feasibility and accuracy by adding compressibility terms directly on the incompressible form of Navier-Stokes equation. Rather than solving for the full compressible form, our slightly-compressible form significantly reduces the complications in establishing stabilization and implementation of its finite element procedure, and yet still captures the fluctuating acoustic waves expected in the compressible form. Using this approach, we demonstrate that generations and propagations of acoustic waves can be accurately captured, without the inclusion of a fully compressible representation of the fluid. Upon the successful verification of its accuracy against analytical and known solutions, we then evaluate the fluid compressibility effect on fluid-structure interactions. Our results show that comparing to an incompressible fluid, a deformable solid generates sound waves while it is driven by the flow and vibrates in the fluid. A periodic volume change in the fluid is also observed, which can be considered as a sound source.
在本研究中，开发了一种用于轻微可压缩等熵流的气动声学流体模型，并在流固相互作用的背景下评估了其压缩性效应。该模型通过直接在不可压缩形式的纳维-斯托克斯方程上添加压缩性项来考虑计算可行性和准确性。与求解完全可压缩形式不同，我们的轻微可压缩形式显著减少了建立其有限元程序的稳定性和实现过程中的复杂性，但仍能捕捉到可压缩形式中预期的波动声波。使用这种方法，我们证明了在不包含流体的完全可压缩表示的情况下，也能准确捕捉声波的产生和传播。在成功验证其相对于解析解和已知解的准确性后，我们接着评估流体压缩性对流固相互作用的影响。我们的结果表明，与不可压缩流体相比，可变形固体在被流体驱动并在流体中振动时会产生声波。还观察到流体中的周期性体积变化，这可被视为一个声源。
