Bulk-Flow Model for the Transition to Turbulence Regime in Annular Pressure Seals Academic Article uri icon


  • An analysis for the prediction of the dynamic force response for annular seals in the transition regime to flow turbulence is presented. A heuristic curve fit connects the laminar friction factor to Moody's turbulent friction factor curve in the transition regime from laminar to fully developed turbulent flows. A universal friction factor model is provided and included in the bulk-flow equations (zeroth- and first-order) governing the flow for small amplitude rotor motions about an equilibrium position. General equations are presented for the shear coefficients and their derivatives required in the bulk-flow model. Flow rates, drag torque and rotordynamic force coefficients are compared with those from traditional analyses for an annular seal experiencing wear and increased clearances leading to off-design operating conditions. Predicted seal force coefficients show physically sound, smooth variations while passing through the transition zone and demonstrate a marked improvement over simpler models which predict sharp discontinuities. © 1996 Taylor & Francis Group, LLC.

author list (cited authors)

  • Zirkelback, N., & San Andres, L.

citation count

  • 24

publication date

  • January 1996