I have a donut shaped sealed pipe attached to a fixed axis by a frictionless bearing , the pipe is filled with an incompressible liquid initially at rest.
Within the pipe I have a small pump which should normally cause a flow around the circuit clockwise.
As this (via the bearing) is an isolated system I understand that the angular momentum is conserved. L=0
By this understanding the internal force on the fluid is countered by the opposite force on the body/pump so it should begin to rotate counter clockwise so that Net L is still zero L=0
While momentum is conserved at L we now have two opposite rotations of the body and the fluid
Is this physically possible ?
Is the relationship complicated by the energy that is put into vorticity ?