I'm doing 2D modeling with COMSOL and my design is about a flow (in the x direction) inside a structure passing square objects, so I thought I could model it on the mechanics of flow between parallel plates.

Unfortunately, the square objects are of the same height as the structure and does not extend for a very long distance in the z direction (height in z direction:width in y direction= 1:100), which is one of the assumptions for that model to work.

Also, the volume of the structure is quite small (10mm x 10mm x 0.1mm) and the inlet resides on the same side as the outlet.

When I tried to force the inlet with fluid velocity based on the flow between parallel plates model, the fluid behaves strangely (like flowing against gravity and stuff ^^;).

Can anyone tell me of any other model that I can base my flow on?