MODELING A NO-SLIP FLOW BOUNDARY WITH AN EXTERNAL FORCE-FIELD
MODELING A NO-SLIP FLOW BOUNDARY WITH AN EXTERNAL FORCE-FIELD
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DOI：
10.1006/jcph.1993.1081
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发表时间：
1993-04-01
影响因子：
4.1
通讯作者：
SIROVICH, L
中科院分区：
文献类型：
--
作者：
GOLDSTEIN, D;HANDLER, R;SIROVICH, L
一种新的技术有关Peskin的浸入边界的方法是用来引入固体表面模拟流场。Navier-Stokes方程允许存在一个外部施加的体积力，该体积力可以在空间和时间上变化。力被选择为沿着期望的表面，并且具有与局部流相反的大小和方向，使得流停留在表面的元件上。对于非定常粘性流，所需力的直接计算通过反馈方案来促进，其中速度用于迭代地确定期望值。特别地，我们从关系式f（x5，t）= α <$t0U（x5，t '）dt'+ βU（x5，t）确定表面体力，其中表面点x5、速度U、时间以及负常数α和β。实例包括二维圆柱绕流，三维湍流槽流，其中一个边界模拟与力场，和湍流槽流超过riblet覆盖的表面。虽然新的方法可以应用于复杂的几何形状的非笛卡尔网格，我们选择使用一个简单的笛卡尔网格。所有的模拟都是在一个单一的计算域没有任何映射的网格与频谱代码。
A novel technique related to Peskin's immersed boundary approach is used to introduce solid surfaces into a simulated flow field. The Navier-Stokes equations permit the presence of an externally imposed body force that may vary in space and time. Forces are chosen to lie along a desired surface and to have a magnitude and direction opposing the local flow such that the flow is brought to rest on an element of the surface. For unsteady viscous flow the direct calculation of the needed force is facilitated by a feedback scheme in which the velocity is used to iteratively determine the desired value. In particular, we determine the surface body force from the relation f(x5,t) = α ∫t0U(x5,t′)dt′+ βU(x5,t) for surface points x5, velocity U, timet, and negative constants α and β. Examples are presented which include 2D flow around cylinders, 3D turbulent channel flow where one boundary is simulated with a force field, and turbulent channel flow over a riblet-covered surface. While the new method may be applied to complex geometries on a non-Cartesian mesh, we have chosen to use a simple Cartesian grid. All simulations are done with a spectral code in a single computational domain without any mapping of the mesh.