Test Results for Sawtooth-Pattern Damper Seals: Leakage and Rotordynamic Coefficients

Test results consisting of direct and transverse force coefficients are presented for eleven, sawtooth pattern, damper seal configurations. The designation damper seal refers to a seal which uses a deliberately roughened stator and smooth rotor to increase the net seal damping force. The designation sawtooth pattern refers to a stator roughness pattern whose cross section normal to the axis of the seal resembles saw teeth with the teeth direction opposing fluid motion in the direction of shaft rotation. The sawtooth pattern yields axial grooves in the stator which are interrupted by spacer elements which act as flow constrictions or dams. Stiffness of sawtooth and round hole pattern seals were comparable. Leakage of maximum damping configurations was greater for sawtooth pattern than for round hole pattern seals; both types of seals leaked substantially less than smooth seals. If damping is sacrificed, sawtooth pattern seals can be designed to leak less than round hole pattern seals.

Test Results for Sawtooth-Pattern Damper Seals: Leakage and Rotordynamic Coefficients Academic Article