I want to simulate a centrifugal pump with a pipe inlet,at present, I only want to calculate only one channel(I have six blades),so the inlet is a sector.the two periodic boundary meet together at the center line of the pipe.when I have a look at the result,the static pressure at the cneter line is as low as -6MPa,so I think the boundary condition may be not correct.who can give me some suggestions?

thank you

set that single line periodic with itself.

i have tried what you said,but there was a piece of error message,which was, "attachment must refer to at least one flux element"