Wear of Brush Seals: Background and New Modeling Approach

Abstract

The brush seal, with superior leakage performance, is emerging as a new sealing technology to effectively control cooling and leakage flows in gas turbine engines. Because the bristles slide against the rotor surface, wear at the contact becomes a major concern as it determines the life and efficiency of the seal. To optimize seal life and efficiency, an in-depth study of the factors causing the seal stiffness is needed, and a good choice of materials must be made. This work investigates some of the past research on brush seal wear. Although considerable research has been done on material selection and tribopairs, the brief survey reveals the lack of reliable analyses to evaluate contact loads and to address heat transfer issues. The complicated nature of bristle behavior under various combinations of pressure load and rotor interference requires computer analysis to study the details that may not be available through analytical formulations. In an effort to meet this need, the present work includes a preliminary computational model of a brush seal. The model consists of a 3-D finite element model of a representative brush seal segment with a mating rotor surface. Preliminary results from the model show reasonable agreement with actual seal behavior.

Presented at the 52nd Annual Meeting In Kansas City, Missouri May 18–22, 1997

KEY WORDS:

• Brush Seals
• Coatings
• Wear

Notes

Presented at the 52nd Annual Meeting In Kansas City, Missouri May 18–22, 1997