三维圆柱体绕流的发展和演化

结合三阶精度格式求解可压缩NS方程，本文研究了绕过三维圆柱体的流动结构，阐明了流动的演化机理。大攻角下，在三维圆柱体背风区形成了一个脱落涡序列，其截面流态非常类似于二维圆柱绕流，主涡、二次涡以及tertiary涡形成了一个层次结构。前一个主涡脱体后，tertiary涡将演化为其后续的新生主涡，并且合并圆柱体对称面另一侧的二次涡。

Development and evolution of flow over three-dimensional cylinder

By solving the three-dimensional (3D) time-dependent compressible laminar Navier--Stokes equations with a finite-volume method incorporating the third-order-accuracy discretization scheme, the flow structure around a 3D cylinder is investigated and its evolution mechanism is presented in thispaper. At high incidence angles, a shed vortex series forms at leeside of the 3D cylinder with its sectional flow pattern very similar to the Karman vortex street developed behind a two-dimensional cylinder. The main, the secondary and the tertiary vortex system compose a hierarchical structure over the 3D cylinder. Each tertiary vortex develops into a new main vortex after the breakaway of its former main vortex, and merges the secondary vortex on its opposite side of the symmetry plane.