preserve faces in volume
 

Hello

I have a horizontal cylinder inside a cube. It is at the centre of the cube and the end faces of cylnder touches the vertical faces of the cube. I want to do a flow simulation over the cylinder (with heat transfer).
So I f I do boolean it is actually removing circular faces of area equal to cylinder top/bottom from the sides of cube. . SO if u look from one end you can see through the cube with cylindrical hole. But I need the end faces of cylinder to be closed. How do I approach it in workbench .