Rotordynamic Analysis

ASD’s advanced rotordynamic analysis capability utilizes component-mode synthesis (CMS) to efficiently and accurately build the complete rotordynamic system representation; e.g., multi-stage engine, engine stand, couplers, generator, ... Our rotordynamic analysis process allows for efficient accounting of the rotor’s structural dynamics, gyroscopic forces, fluid-structure interaction forces, external time/frequency dependent forces, imbalances, weight, hydrodynamic bearings and seals, and nonlinearities such as deadbands. This capability is also utilized to evaluate the engine for transient events such as engine start-up, shut-down, generator short-circuit, and malsynchronization.

ASD's rotordynamic analysis capability has been utilized to complete over 40 analysis cycles of the GE LM5000 (35 MW) dual-spooled gas turbine engine. The LM5000 engine consists of a five-stage low pressure compressor, a fourteen-stage high pressure compressor, a two-stage high pressure turbine, a five-stage low pressure turbine and a three-stage, aerodynamically coupled power turbine. Results from ASD's coupled lateral/torsional rotordynamic analysis of the LM5000 compared extremely well with field data.

ASD has also been selected to perform the rotordynamic analyses involving the GE LM6000 (40 MW) dual-spooled gas turbine engine. The LM6000 consists of a five-stage low pressure compressor, a fourteen-stage high pressure compressor, a two-stage high pressure turbine, a five-stage low pressure turbine which directly drives the low pressure compressor and generator.

Case Histories

  • Over 40 cycles of lateral and torsional rotordynamic analyses for the LM5000 engine/integrated assembly loads and vibrations predictions involving nominal rotor unbalance, blade-out contingencies, and torsional cases. Design/analysis of an isolated mounting system and comparison of analysis to field data measurements.
  • Multiple cycles of lateral and torsional rotordynamic analyses for the LM6000 engine/integrated assembly loads and vibrations predictions involving nominal rotor unbalance, blade-out contingencies, transient startup, shutdown, short circuit, and malsynchronization. Modeling of and loads/vibrations predictions at the generator hydrodynamic bearings.