My problem like is â€" A circular pipe of length of 1m exactly in between the center a series of baffles are sitting inside. I am interested to check the pressure drop across baffles. I am stuck in applying the BC,s

At the inlet of the circular pipe â€" Velcity inlet At the exit of the pipe â€" Outflow. In the baffle front face i.e., facing inlet â€" inlet vent In the baffle back face ie., facing exit â€" outlet vent. Remaining all other faces - Wall

I am keep solving this problem, using the above BC,s I cant. Then I changed the inlet and outlet vent to Interface, again I can't. Can anybody help me out in this?

Did you use Gambit to model the geometry? Are you physically modeling the baffles, or are you trying to simulate the baffles with a BC?

I'm assuming you used Gambit, and assuming that you actually modeled the baffles.

If the geometry is connected (i.e., where ever two volumes touch they share a common face) then you don't need to apply any BCs to these faces. Gambit will simply ignore the faces and write a continuous volume for the mesh.

If the geometry isn't connected, then you need to define an interface BC for each of the faces which touch (i.e. if volume A and volume B touch, then you have to define an interface BC for the face on volume A and a separate interface BC for the face on volume B). Then in Fluent you create a single interface using the Define->Grid Interfaces tool.

If you're modeling a continuous pipe and you're trying to fake the baffles using a BC then you need a lot of information about your baffle already. A porous-jump is probably what you'd use if you had that information. Otherwise you should model the actual baffles.

Hope this helps, and good luck, Jason