Affiliations: Department of Mechanical Engineering, Universidad
Nacional Autonoma de Mexico (UNAM), Campus Juriquilla, Queretaro, Mexico | Department of Mechanical Engineering, Universidad
Nacional Autonoma de Mexico (UNAM), Campus Juriquilla, Queretaro, Mexico
Note: [] Corresponding author: Leonardo Urbiola-Soto, Adjunct Professor,
Department of Mechanical Engineering, Universidad Nacional Autonoma de Mexico
(UNAM), Campus Juriquilla, Queretaro 76230, Mexico. E-mail:
[email protected]
Abstract: Nearly a century ago, the liquid self-balancing device was first
introduced by M. LeBlanc for passive balancing of turbine rotors. Although of
common use in many types or rotating machines nowadays, little information is
available on the unbalance response and stability characteristics of this
device. Experimental fluid flow visualization evidences that radial and
traverse circulatory waves arise due to the interaction of the fluid backward
rotation and the baffle boards within the self-balancer annular cavity. The
otherwise destabilizing force induced by trapped fluids in hollow rotors,
becomes a stabilizing mechanism when the cavity is equipped with adequate
baffle boards. Further experiments using Particle Image Velocimetry (PIV)
enable to assess the active fluid mass fraction to be one-third of the total
fluid mass. An analytical model is introduced to study the effects of the
active fluid mass fraction on a flexible rotor supported by flexible supports
excited by bwo different destabilizing mechanisms; rotor internal friction
damping and aerodynamic cross-coupling. It is found that the fluid radial and
traverse forces contribute to the balancing action and to improve the rotor
stability, respectively.
