Analysis of tilting-pad oil seals for high pressure centrifugal compressors

Oil ring seals are one major source of instability in high pressure centrifugal compressors. This thesis presents a method for analysis of an improved seal concept that has been used in very high pressure designs (900 PSI). The improved design uses a combination of ring seals and tilting pad bearing elements. The stable tilting pad is used to center the heavily grooved seal element. The eight stiffness and damping coefficients which represent the hydrodynamic forces between the journal and the seal assembly are computed by an automated computer code for evaluation of both the standard ring seal and the tilting pad elements. Both synchronous and nonsynchronous steady state characteristics have been included in the analysis. The nonsynchronous whirl of the rotor and its effects on the stiffness and damping coefficients of a 5 tilting pad seal have been given in the form of design curves. The effect of pad inertia which has been neglected in many bearing analysis codes has been incorporated in this seal analysis, and allowed the determination of the exact cross coupling stiffness and damping coefficients.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1988

Author dc:creator

• Salem, Khlifi

Chair dc:contributor.committeechair

• Kirk, R. Gordon

Committee members dc:contributor.committeemember

• Mitchiner, Reginald G.
• Moore, John

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-11212012-040039

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/45937