Direct Numerical Simulation of Flow Past Elliptic Cylinders
Direct Numerical Simulation of Flow Past Elliptic Cylinders
复制标题
DOI：
10.1006/jcph.1996.0065
复制
发表时间：
1996-03
影响因子：
4.1
通讯作者：
R. Mittal;S. Balachandar
中科院分区：
文献类型：
--
作者：
R. Mittal;S. Balachandar
椭圆柱体上的流动可以被认为是一系列海崖体上流动的原型，因为几何形状允许人们研究厚度和攻角对流场的影响。因此，对这种流动的仔细研究应该对非定常分离现象和海崖体尾流的结构提供有价值的见解。考虑到这一点，谱配置技术已被开发来模拟全三维不可压缩流椭圆柱，不像谱元素和光谱多域技术，这里的流动是在一个单一的域解决。方程离散上的贴体椭圆柱网格和属性的度量与此坐标系被用来解决控制方程在一个有效的方式。文中还详细讨论了包括流入和流出边界条件以及时间离散化在内的关键问题，希望这将有助于今后类似流动的模拟。最后，我们给出了一系列流动和几何参数的二维和三维模拟结果。结果与现有的实验数据进行了比较，发现重要的数量，如斯特劳哈尔数和阻力系数匹配以及与既定的值。
Flow over elliptic cylinders can be considered prototypical of flow over a range of bluff bodies since the geometry allows one to study the effect of both thickness and angle-of-attack on the flow field. Therefore, a careful study of this flow should provide valuable insight into the phenomenon of unsteady separation and the structure of bluff body wakes. With this in mind, a spectral collocation technique has been developed to simulate the full three-dimensional incompressible flow over elliptic cylinders and, unlike spectral element and spectral multidomain techniques, here the flow is solved in a single domain. The equations are discretized on a body-fitted elliptic cylindrical grid and properties of the metric associated with this coordinate system are used to solve the governing equations in an efficient manner. Key issues including the inflow and outflow boundary conditions and time-discretization are discussed in detail with the hope that this will facilitate future simulations of similar flows. Finally, we present results of two- and three-dimensional simulations for a range of flow and geometric parameters. The results are compared with available experimental data and it is found that important quantities like Strouhal numbers and drag coefficients match well with established values.