Example 2: 3D Cylinder

The next example of this tutorial analyses another case, that of the three-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).

Please note that this example cannot be run with the limited version of Tdyn RANSOL module.

As in the 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 (see Figure 20).

-         flow passing a cylinder

-         viscous, turbulent case

-         Reynolds number of 100

Figure 20 Geometry for a 3D analysis of a cylinder

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)

-           h=1 10-2       (kg/m.s)

This gives

Re = 100