i am working on single phase natural circulation loop. i want to make grid in bfc for circular pipe which is a rectangular loop. i want to close the loop how 2 close the loop. i am getting one error msg ,yc has revesed sign because grid supllid was left handed

RE left-handed grid, you've put you ijk origin in the wrong place. Shift it over to the other side of the mesh. If you're using a polar mesh, just rotate the circular plane around the other way.

To close the loop, you need to define some cyclic boundary conditions at the extents where the loop closes.

To close the loop, which type of cyclic boundary conditions shoud i specify at the extents where the loop closes.

i am working on single phase natural circulation loop. i have make grid in bfc for circular pipe which is a rectangular glass loop. the loop is filled with water. heater is placed at bottom & cooler is at top. i want to solve for velocites,press& temp.how to solve for this. how to get convergence

i am also working on the same modeling. you have already started some months ago, you might have proceeded a long way , please share with me. with regards Narendar