Display Full Text | Download Full Text
1.60 MB PDF file

Degree

Master of Science, University of Akron, Mechanical Engineering, 2007.

Abstract

The non-contacting nature of finger seal technology provides a compliant seal which allows both axial and radial adjustments to rotor excursions, without loss of physical integrity or sealing capability. The same cannot be said of labyrinth and brush seals. This fact, along with their relatively low cost, could make finger seals a superior choice in many situations. The performance of twelve different finger seal assemblies has been evaluated. The assemblies are created by combinations of four different sets of finger seal laminates and three front plate designs. Three laminate sets feature a high pressure padless layer, and a padded low pressure layer which generates lift and gives the seal its compliant nature. The fourth laminate set also features an additional padded layer which interlocks with the original low pressure layer, and eliminates leakage between adjacent lifting pads. The original front plate serves only to clamp the laminates to the test rig, while the other two are designed to help restrict flow through the assembly, and force more air under the pads, improving lifting capability. Seal performance is evaluated through a set of parametric studies in which the pressure differential across the seal is brought to 20 psid, and the rotor speed is brought from rest to 15 krpm in increments of 5 krpm. A series of static tests were conducted to ascertain the performance of seal combinations at pressures greater than 20 psi. The study shows that all of the finger seal combinations lift effectively, and experience only minor wear during startup. The double pad design outperforms the original three seals, by providing lower leakage rates and operating temperatures. The modified front plate designs have shown to reduce leakage and improve lifting capability, making them an excellent supplement to an assembly of finger seal laminates.

Subject Headings

Engineering, Mechanical

Keywords

finger seals; compliant seals

Advisor

Minel J. Braun

Document number: akron1195226720
Permalink: http://rave.ohiolink.edu/etdc/view?acc_num=akron1195226720

This ETD has been downloaded 390 times (through March 2013)