论文标题
考虑空气反馈机制的深层腔的数值研究
Numerical investigation of a deep cavity with an overhanging lip considering aeroacoustic feedback mechanism
论文作者
论文摘要
在现代运输系统中，乘客的舒适感受到流动引起的噪音的极大影响。在这项研究中，我们研究了一个通用的深腔，嘴唇悬垂着，模仿了车辆的门间隙，该腔间隙在两个不同的自由流速度下被空气溢出，26.8m/s和50m/s。湍流边界层和声波与腔的几何形状相互作用并形成强大的反馈机制。在目前的工作中，我们关注可压缩的湍流结构的细节及其有关速度，边界层以及域维度的变化，用于混合气声工作流中后来的声学模拟。此外，我们通过对跨度方向进行声学活跃的流动结构进行连贯的研究来验证该应用的声学计算结构域从3D降低到2D的可行性。还评估了有关涡流形成和涡流边缘相互作用的三维泰勒·戈特勒涡流的作用。对于较低的速度（26.8m/s）来说，我们发现了一种特殊的涡旋 - 边缘相互作用，即完全剪裁的交替序列和随后的部分逃脱。最后，我们将以前的压力谱中未知峰分配给其相应的机制。
In modern transport systems, passengers' comfort is greatly influenced by flow-induced noise. In this study we investigate a generic deep cavity with an overhanging lip, mimicking a door gap in a vehicle, that is overflowed by air at two different free stream velocities, 26.8m/s and 50m/s. The turbulent boundary layer and the acoustic waves interact with the cavity's geometry and form a strong feedback mechanism. In the present work, we focus on the details of the compressible turbulent flow structures and their variations concerning the velocity, the boundary layer as well as the domain dimensionality for a later acoustic simulation within a hybrid aeroacoustic workflow. Furthermore, we verify the feasibility of reducing the acoustic computational domain from 3D to 2D for this application by conducting a coherence study of acoustically active flow structures in the spanwise direction. The role of the three-dimensional Taylor-Görtler vortices from the recirculation regarding the vortex formation and the vortex-edge interaction was also evaluated. Remarkably for the lower approaching velocity (26.8m/s), we found a special vortex-edge interaction, namely an alternating sequence of complete clipping and a subsequent partial escape. Lastly, we assigned previous unknown peaks in the pressure spectrum to their corresponding mechanisms.
