How to impose a constant temperature BC on a porous cylinder surface?
 

I'm a new beginner with openfoam. I want to impose a constant temperature BC on a porous cylinder surface inside fluid. The porous cylinder is created by editing the N-S equation and water can go inside the porous cylinder so i can't simply create walls.

I tried topoSet+createBaffles, and set the internal walls' type as ''patch'', but it seems fluid was blocked by the internal walls.

So my question is how to create internal wall with zero thickness that won't block the fluid and I can also set it's temperature as a constant value. Or maybe there are other ways?

Many thanks.