Experimental Analysis of the Leakage Characteristics of Three Types of Annular Segmented Seals

The present paper presents an experimental analysis of the leakage characteristics of three kinds of segmented seals. The segments of the first seal have smooth pads while the second seal has pads with pockets. The pads of the third seal are smooth but the rotor is textured with inclined grooves. The pockets or the textures lift the segments from the rotor and create a radial clearance. This is reflected by the leakage flow rate, the friction torque, and the seal's temperature. These characteristics are hereby measured on a dedicated test rig. The presented results are dimensionless, the measured values for the three types of seal types being divided by the same maximum value. This makes it possible to compare the performance of different segmented seal technologies and to evaluate the compromise between low leakage and enhanced lifespan. The assumptions made on the opening of the segmented seal with pockets during the tests are finally verified with a simple analytical model.