论文标题
用于使用前沿涡流脱落的流量的减少排序离散涡流方法
A Reduced-Order Discrete-Vortex Method for Flows with Leading-Edge Vortex Shedding
论文作者
论文摘要
前沿涡流（LEV）的形成是不稳定流动的关键特征，但在高保真度计算中建模却很昂贵。基于离散涡流元素的低阶方法能够捕获这些流动的物理行为，特别是在使用标准增强时，该标准模拟了前缘维持吸力的能力。这些模型的速度明显快于高阶方法，但是随着涡流元素不断脱落并将其引入尾流，它们的费用仍然增长，实际上是$ \ Mathcal {O}（o}（n^2）$问题。这项工作提出了通过将LEV相干结构中的涡旋元素限制为N，从而加快了前缘吸力参数离散涡流方法（LDVM），从而将其名称命名为N-Lea-lev LDVM。与原始LDVM模型和计算流体动力学（CFD）模拟相比，N-LEV LDVM方法正确近似流量，直到LEV分离点为止，N-Lev LDVM无法建模。我们建议通过在LEV文献中研究的两个物理分离标准重新引入这种行为，这是LEV中最大循环的阈值和后缘流动的逆转。我们证明了N-LEV LDVM方法准确预测这两种机制的分离的能力，与实验结果相比，这两种机制都发生了这种分离，这为它们纳入了该方法。
The formation of the leading-edge vortex (LEV) is a key feature of unsteady flows past aerodynamic surfaces, but is expensive to model in high fidelity computations. Low-order methods based on discrete vortex elements are able to capture the physical behavior of these flows, in particular when enhanced with a criterion that models the ability of the leading edge to sustain suction. These models are significantly faster than high order methods, but their expense still grows as vortex elements are continuously shed and convected into the wake, in effect an $\mathcal{O}(n^2)$ problem. This work proposes accelerating the leading-edge suction parameter discrete vortex method (LDVM) by limiting the number of vortex elements in the LEV coherent structure to N, hence giving the name to the method N-LEV LDVM. The N-LEV LDVM method correctly approximates the flows in comparison with the original LDVM model and computational fluid dynamics (CFD) simulations until the point of LEV detachment, which N-LEV LDVM is unable to model. We propose reintroducing this behavior via two physical detachment criteria studied in LEV literature, a threshold of maximum circulation in the LEV and trailing edge flow reversal. We demonstrate the ability of the N-LEV LDVM method to accurately predict the instant in time this detachment occurs for both mechanisms in comparison with experimental results, laying the ground for their incorporation into the method.
