Rotordynamics of a 2-Phase Flow Twin Screw Pump Conference Paper uri icon


  • Twin-screw pumps are positive displacement machines. Two meshing screws connected by timing gears push the fluid trapped in the screw cavities axially from suction to discharge. Available steady state hydraulic models predict pump performance and axial pressure distribution in the chambers in single and two phase flow conditions. However, no model is available for their rotordynamics. Due to the helix angle of the screw, the pressure distribution around the rotor is not balanced; giving rise to both static and dynamic lateral forces. The work presented here introduces a starting point for rotordynamic analysis of twin screw-pumps. We first show that the screw rotors geometry can be represented by axisymmetric beam elements. Second, we extend the steady state hydraulic model to predict both the static and dynamic lateral forces resulting from the unbalanced pressure field. Finally, hydraulic forces are applied to the rotor to predict static, synchronous and nonsynchronous responses. Predictions of the dynamic pressure were compared to measurements from the literature and were found to be in good agreement. Copyright © 2012 by ASME.

author list (cited authors)

  • Muhammed, A., & Childs, D. W.

citation count

  • 1

publication date

  • June 2012