Overview

Case studies given in this section relate to actual types of turbomachinery calculations performed in industry. They follow directly from the theoretical sections to permit the reader to immediately see how the tools can be applied to address rotating machinery torsional vibration calculations and problems. Some readers may prefer to bypass this section on the first run-through of the book and return to it later after reviewing the remaining more descriptive sections.

It is impractical to solve realistic turbomachinery vibration problems without the use of computers. Hence, the methodologies defined in Chaps. 6 through 8 were coded into a computer program that is documented in App. E, and this program was used as required in the studies. Interpretation of all the computer-generated results is given.

The case studies in this chapter can be used in the following ways:

• To evaluate how turbomachines are modeled and how calculations are performed for torsional vibration analysis and get an appreciation for what the results mean. It is not necessary to replicate the computer simulations.

• To confirm the case study results with other computer software available to the reader, make comparisons, and evaluate different modeling assumptions.

• As examples for use in classroom or training workshop environments.

The case studies start with relatively simple ones and progress to quite complex ones associated with rotating machinery transient vibration evaluations. The case studies are covered as follows:

• Section 9.1 deals with assembly of vibration models and global matrices and relates to Chaps.