Perforated Plates

Hi,

I'm building a flow simulation of a room where we are supplying air down into a false ceiling. The false ceiling has a series of perforated panels to supply laminar flow into the conditioned room. I used the lids tool to create the perforated panels in the ceiling and then used the perforated plates tool on the lids but Solidworks seems to see them as solid objects and won't let air pass through them.

After doing a search online this seems to be a common problem and people recommend using the porous media tool instead, so i have done this and appear to be getting the correct results. But i'm curious why the perforated plate tool doesn't work, Has anyone had any success using it?

Thanks,

Josh

SolidworksFlow Simulation