Carrier-Domain Method for High-Resolution Computation of Time-Periodic Long-Wake Flows
Carrier-Domain Method for High-Resolution Computation of Time-Periodic Long-Wake Flows
复制标题
时间周期长尾流高分辨率计算的载域法
DOI：
10.1007/s00466-022-02230-6
复制
发表时间：
2022
影响因子：
4.1
通讯作者：
and Y.Zhang
中科院分区：
文献类型：
--
作者：
Y.Liu;K.Takizawa;T. E.Tezduyar;T.Kuraishi;and Y.Zhang
我们引入了载波域方法（CDM），用于时间周期长尾流的高分辨率计算，其成本效益使计算变得实用。 CDM 与 24 年前推出的多域方法密切相关，最初也是为了经济有效地计算长尾流，后来扩展范围以涵盖其他类别的流问题。在 CDM 中，计算域沿自由流方向移动，其速度保持下游计算边界的流出性质。当计算域移动时，流入平面的速度是从先前当平面当前位置被移动域覆盖时计算的速度中提取的。某一时刻所需的流入数据是从时间上可追溯至多个周期的一个或多个时刻中提取的。使用具有合理长度的高分辨率移动网格计算长尾流肯定比使用覆盖整个尾流长度的固定网格计算更具成本效益。我们还推出了 CDM 版本，其中计算域以离散方式而不是连续方式移动。为了演示 CDM 的工作原理，我们使用计算域以连续方式移动的版本来计算经过雷诺数为 100 的圆柱体的 2D 流动。在此雷诺数下，流动具有易于辨别的涡旋脱落频率以及广泛发布的升力和阻力系数以及斯特劳哈尔数。计算圆柱体下游 350 个直径范围内的尾流，该距离足以看到次级涡街。计算采用时空变分多尺度方法和等几何离散化进行；基函数在空间上是二次 NURBS，在时间上是线性的。结果显示了 CDM 在时间周期长尾流高分辨率计算中的强大功能。
We are introducing the Carrier-Domain Method (CDM) for high-resolution computation of time-periodic long-wake flows, with cost-effectives that makes the computations practical. The CDM is closely related to the Multidomain Method, which was introduced 24 years ago, originally intended also for cost-effective computation of long-wake flows and later extended in scope to cover additional classes of flow problems. In the CDM, the computational domain moves in the free-stream direction, with a velocity that preserves the outflow nature of the downstream computational boundary. As the computational domain is moving, the velocity at the inflow plane is extracted from the velocity computed earlier when the plane’s current position was covered by the moving domain. The inflow data needed at an instant is extracted from one or more instants going back in time as many periods. Computing the long-wake flow with a high-resolution moving mesh that has a reasonable length would certainly be far more cost-effective than computing it with a fixed mesh that covers the entire length of the wake. We are also introducing a CDM version where the computational domain moves in a discrete fashion rather than a continuous fashion. To demonstrate how the CDM works, we compute, with the version where the computational domain moves in a continuous fashion, the 2D flow past a circular cylinder at Reynolds number 100. At this Reynolds number, the flow has an easily discernible vortex shedding frequency and widely published lift and drag coefficients and Strouhal number. The wake flow is computed up to 350 diameters downstream of the cylinder, far enough to see the secondary vortex street. The computations are performed with the Space–Time Variational Multiscale method and isogeometric discretization; the basis functions are quadratic NURBS in space and linear in time. The results show the power of the CDM in high-resolution computation of time-periodic long-wake flows.