Theoretical and experimental analysis for leakage rate and dynamic characteristics of herringbone-grooved liquid seals

Abstract

In this paper, a theoretical analysis method for leakage rate and dynamic characteristics of herringbone-grooved liquid seals is proposed. Steady-state velocities and leakage rate are figured out first with the inertia term of the fluid combined with mass conservation within the seals. Subsequently, the rotordynamic coefficients are solved based on the investigation of Iwatsubo and Childs. Laboratory tests were performed on a specially designed test rig. Detailed comparisons between the experimental results and theoretical predictions show a good agreement on the leakage rate and hydraulic forces for five model seals, which provide an evidence of validation of the analysis method developed in this paper. Moreover, the influence of rotational speed and pressure difference on the leakage rate and rotordynamic coefficients of herringbone-grooved seals is discussed. The results show that the operating conditions and seal structures greatly influence the sealing and rotordynamic performances, which is helpful for designing herringbone-grooved seals.