Rotordynamic Coefficients and Leakage Flow of Circumferentially Grooved Liquid-Seals

Abstract

Measured leakage flow and rotordynamic coefficients for six, circumferentially-grooved, liquid seals are compared to predictions based on Nordmann et al.’s (1986) grooved seal model. The grooved seal model uses a modification of Hirs’ (1973) bulk-flow theory to account for the difference in friction factor in the circumferential and axial directions due to the grooves. Also, the model uses an average groove depth to account for the circumerential flow in the grooves. Comparison of the predicted and measured friction factors in grooved-seals with orbiting-rotors shows a poor correlation. In spite of the poor friction-factor correlation, the accuracy of predictions for rotordynamic coefficients are comparable to predictions of Childs et al. (1988) and Childs and Kim (1986) for smooth and hole pattern seals.