Turbulence

Reynolds number

Square (algebra)

Statistical physics

Physics

Mathematics

Cylinder

Wake

Geometry

Mechanics

Physics of Fluids

The wake of a square cylinder is investigated for Reynolds number Re < 107. Two-dimensional (2D) laminar simulation and three-dimensional (3D) large-eddy simulation are conducted at Re ≤ 1.0 × 103, while experiments of hotwire, particle image velocimetry, and force measurements are carried out at a higher Re range of 1.0 × 103 < Re < 4.5 × 104. Furthermore, data covering a wide Re range, from 100 to 107, in the literature are comprehensively collected for discussion and comparison purposes. The dependence on Re of the recirculation bubble size or vortex formation length, wake width, shear-layer transition, time-mean drag force, and Strouhal number is discussed in detail, revealing five flow regimes, each having distinct variations of the above parameters. With increasing Re, while the streamwise recirculation size enlarges at Re < 50 (steady flow regime), the vortex formation length reduces at 50 < Re < 1.6 × 102 (laminar flow regime), remains unchanged at 1.6 × 102 < Re < 2.2 × 102 (2D-to-3D transition f...

Dependence of square cylinder wake on Reynolds number