Introduction to Pump Rotordynamics
Abstract
The lecture introduces the basic problems in the rotordynamics of turbomachinery, excessive vibration and instability. The acceptable performance of a turbomachine depends on the adequate design and operation of the bearing and seal elements supporting a rotor. Descriptions of the basic principles of lubrication follow with details on the operation of hydrodynamic and hydrostatic lubricated bearings and seals. The differences among these elements are highlighted with a brief account on their effects on rotordynamics. The basic equations for the modeling of linear rotor-bearing systems are given along with an example for the rotordynamics of a multiple stage compressor. Pump rotordynamics is introduced noting the major difference with other rotating systems, i.e. hydraulic side loads, static and dynamic, due to pressure changes in the volute and flow conditions in an impeller, dynamic forces from seals neck ring and interstage and balance pistons, and impeller-rotor interaction forces. Accounting for the action of these elements is of importance to adequately predict the performance and troubleshoot the rotordynamics of high performance pumps. An example of rotordynamic analysis of a multiple-stage liquid pump stresses the differences between wet and dry predictions, i.e. operation with and without the pumping liquid.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 2006
- Accession Number
- ADA476496
Entities
People
- Luis S. Andres
Organizations
- Texas A&M University