
Create the larger
area, then the area defining the plate. 

Subtract the
smaller area from the larger plate. 

Define
the Element Properties as a 2D Air ElementDefine the Material
Properties of the Air Element (Density and Viscosity are the
important qualities) 

Mesh the plate with
a mesh size of 0.01 on the edges of the inner plate, and 0.2
on the edges of the outer plate. 

Apply Boundary
Conditions (No Slip along the edges of the inner plate, velocity along
the left line of the large plate, and Atmospheric Pressure (P=0 in
ANSYS) along the top, right and bottom lines of the large plate.


Iterate 400 times
and solve. (Ideally the iteration count would be at least several
thousand times to make sure that the solution converges… but
computational time dictates that in order to be able to solve the
problem in a reasonable amount of time, the iteration number should be
trimmed down to 400) 

Plotting the
Velocity distribution in the X direction, this is the answer you
should obtain with 400 iterations: 