Just a suggestion related to Bryan post.
Even the pig has constant speed (and consequently zero acceleration in the direction of velocity), in a circular motion through a curve will be a centrifugal/ centripetal acceleration (due to change of the direction of vector velocity, not necessary to the change in value).
For such case, the "lateral" acceleration may be constant for the pig but is a moving vector for the bend, so is dynamic in nature for your system. You can try with this approach when apply acceleration.
Note that in fact the problem is far complicated due to fluid mechanics involved and how the differential pressure is consolidated through pig motion (and consequently may be an acceleration also in velocity direction, more familiar -because is similar to the "regular" acceleration of a car, as example- but hard to guess it in your case).
Again in my opinion, somehow the problem is similar to a single slug traveling through bends.
Edited by mariog (07/19/21 02:33 AM)