Session: 23-08 Annular Seals

Paper Number: 152781

Dynamic Characterization of Annular Gas Seals With 3D-Printed Texture Patterns 

Annular gas seals play a significant role in the overall efficiency of compressors. Balance piston seals in centrifugal compressors experience large pressure differentials and can develop significant rotordynamic forces. Textured seals, such as hole-pattern-stator seals, have been widely used as balance piston seals. 3D-printing technology has become increasingly accessible for rapid prototyping, allowing for the variation of geometric parameters in textured seals. The paper explores the feasibility of leveraging 3D printing for component-level seal testing. Leakage and rotordynamic force coefficients are presented for two diamond-shaped hole damper seals 3D-printed with carbon fiber reinforced Nylon. The first seal features a constant hole size across the seal land to serve as a baseline. The second seal is configured with holes of varying cross-sectional areas decreasing in the flow direction. The test conditions include three rotor speeds (10, 15 and 20 krpm) and three inlet-to-outlet pressure ratios (0.25, 0.35 and 0.43) at inlet pressure of 19.3 bar-a. Compared to the diamond seal (baseline seal), the variable-diamond seal (VDH seal) developed larger direct stiffness and damping coefficients. At some conditions, the VDH seal shows same sign cross-coupled stiffness which tends to distort the orbit and does not contribute to destabilizing forces. The VDH yields a higher effective damping than that identified for the baseline seal as well as a lower cross-over frequency. However, the noted differences in dynamic performance between the two seals decrease as the speed increases. 

Presenting Author: Seung-Hyeop Hyun Turbomachinery Laboratory at Texas A&M University

Presenting Author Biography: Seung-hyeop Hyun is a senior Ph.D. student at Turbomachinery Laboratory of Texas A&M University. His research focuses on experimental studies on component-level testing mainly with annular gas and liquid seals.

Authors:

Seung-Hyeop Hyun Turbomachinery Laboratory at Texas A&M University
Andrew Moody Turbomachinery Laboratory at Texas A&M University
Adolfo Delgado Turbomachinery Laboratory at Texas A&M University