Effects of Different Rub Models on Simulated Rotor Dynamics
Abstract
Using a direct-integration, transient-response rotor dynamics computer code, the response of turbine engine rotors to two different blade tip - seal interference rub models was studied. The first model, an abradable seal rub model, is based on an energy-loss-per-unit-volume theory. It is applicable to a ceramic turbine blade tip seal. The second, a smearing model, is based on viscous hydrodynamic theory. It is applicable to a metallic blade tip seal. The results from these two models were compared with those from a previously studied model based on dry friction theory. The abradable model was very sensitive to small changes in the energy per unit volume, and once a threshold was exceeded, the rotor went into backward whirl. The amplitude seemed to grow without limit. This similar to the dry friction model when the coefficient of friction exceeded a particular threshold. The smearing model was not as sensitive to small changes in the viscosity, but a threshold viscosity was found. When it was exceeded, the rotor went into backward whirl, but the amplitude seemed to grow to a finite limit.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1984
- Accession Number
- ADA138495
Entities
People
- Albert F. Kascak
- John J. Tomko
Organizations
- National Aeronautics and Space Administration