Rotordynamic coefficients of circumferentially-grooved liquid seals using the averaged Navier-Stokes equations

The paper presents a method to calculate the rotordynamic coefficients of circumferentially-grooved liquid seals operating in centered position and turbulent flow regimes. The method is based on the integration of the averaged Navier-Stokes equations and uses a coordinate transformation proposed by Dietzen and Nordmann (1987). The effect of the coordinate transformation on the components of the stress tensor is included in the first order transport equations. To ensure grid independent solutions, numerical boundary conditions for the first-order velocities were formulated using the logarithmic law. The perturbation of the turbulent viscosity was also considered. A pressure recovery effect at the exit section was included in the first order mathematical model. The method is validated by calculations for straight and circumferentially-grooved seals. Comparisons with experimental and theoretical results show a good agreement for straight seals and for seals with few grooves, and a reasonable agreement for severe industrial cases (high Reynolds numbers and large number of grooves).