Use of STAR CD for viscoplastic flow

The Mesh

III.1 The structure

    The problem is two-dimensionnal and the studied flow occurs in a chanel. The geometry of this chanel is composed of two walls, one entry and one outlet. The length of this chanel is 2 meters and the width is 0,2 meters. The geometry and the mesh had been created under STAR CD. Then one has used the post processing of STAR CD to study the flow in the chanel.

    We created a 3D mesh because STAR CD only uses and solves with 3D ones. Thus, only one cell has been created in the z-direction. The number of cells used were:
- 200 cells have been used in the x-direction
- 20 cells have been used in the y-direction

The mesh obtained is the following one:

With this view, you can see the end of our mesh:

III.2 The boundary conditions

    We used simple boundary conditions to limit the mesh.
Upstairs and downstairs, we defined two walls (colored in white). On the front side and the back side, we defined symmetries which described an infinite domain (colored in blue). On the left, we defined an inlet (colored in red) and , on the right, we defined an outlet (colored in green).

We imposed as limit conditions the inlet velocity which was fixed at Ux=0.001 m/s as you can show it on the following picture:

    The material used was liquid water. We used such a low inlet velocity to be sure we had laminar flow. Furthermore, we calculated the Reynolds number and we found Re=200.