Error: Sheet bodies are not supported by auto inflation
 

Hi,

I'm trying to mesh an open channel with a complex bathymetry to assess flow field. When I try to use Inflation to create represent well the boundary layer I get the following error:

"Sheet bodies are not supported by auto inflation"

Does anybody knows what is the definition of sheet bodies? and, how I can solve this problem?

The figure below shows the modeling domain. The upper bound has a velocity inlet boundary condition (bc), the bottom of the channel has a wall bc, the outlet a pressure outlet bc, and the top face, hidden in the figure, a symmetry bc.

Thank you!

http://imageshack.com/a/img537/2421/atjd3H.jpg