Influence of Induced Unbalance on Subsynchronous Vibrations of an Automotive Turbocharger

Rotordynamic instability is present in most or all automotive turbochargers. High subsynchronous amplitudes can cause a variety of problems in areas such as mechanical failures, emissions regulations and rotor design. Self-excited vibrations from sources of damping can lock in at lateral natural frequencies causing dangerously high vibration levels. The resulting high-amplitude conical and bending modes can be reduced in order to achieve a more robust system. This research focuses on the relationship between synchronous and subsynchronous amplitude levels. It is theorized that an increase in unbalance could cause a reduction in subsynchronous vibration amplitudes. Through the use of a custom turbocharger, a series of unbalances were applied to both the turbine and compressor wheels and the resulting amplitudes were recorded off a modified compressor nut. The resulting data were reduced and are presented at the end of this paper.

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

2009

Author dc:creator

• Sterling, John Anthony

Chair dc:contributor.committeechair

• Kirk, R. Gordon

Committee members dc:contributor.committeemember

• Kasarda, Mary E.
• Wicks, Alfred L.

• Turbocharger
• Instability
• Subsynchronous
• Unbalance

Statement dc:rights

• In Copyright

Licence dc:rights.uri

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

Dc Identifier Other

etd-07132009-192300

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/33996