I would like to average the velocity at the exit of a pipe. I have created a zone of a slice at the exit plane and set a cut off for the color contour so that it only includes the velocity contour at the exit of the pipe and not the atmospheric domain. I then performed integration on that zone to find average z-velocity. However, I believe the integration is over the entire domain and not just inside the exit of the pipe as I would like. Is there a way to only calculate the average z-velocity at the exit of the pipe?