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 posit ion and turbulent flow regimes. The method is based on the integration of the averaged Navier-Stokes equations and uses a coordinate transfo rmation proposed by Dietzen and Nordmann (1987). The effect of the coo rdinate transformation on the components of the stress tensor is inclu ded in the first order transport equations. To ensure grid independent solutions, numerical boundary conditions for the first-order velociti es 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 circumferenti ally-grooved seals. Comparisons with experimental and theoretical resu lts show a good agreement for straight seals and for seals with few gr ooves, and a reasonable agreement for severe industrial cases (high Re ynolds numbers and large number of grooves).