Example 5: 2D Cylinder

The fifth example of this tutorial analyses a case of two-dimensional flow passing a cylinder in the low Reynolds range.

We choose a Reynolds number of Re = 100, for which we expect a vortex street in the wake of the cylinder (the well known von Kármán vortex street).

As in the two previous examples the geometry consists of a box that represents the control volume, which contains the body to be studied in this case the circular cylinder.

Flow passing a cylinder

Viscous, turbulent case

Reynolds number of 100

The Reynolds number is calculated as in the cavity flow example. In this case we chose for the characteristic length of the problem, L, the diameter D of the cylinder.

The example's parameters are

 

D = 1 m

v = 1 m/s

r = 1 kg/m3

m= 1 10-2 kg/ms

This gives

Re = 100