dc.description.abstract | The reliability of centrifugal compressors for the most part depends on the reliable operation of impellers. Most of the time, damage to impellers is due to mechanical fatigue. Fatigue damage has been observed in blades, discs, and covers. The damage is due to alternating stress resulting from vibration of structure. Alternating force can excite natural mode(s) of vibration that in turn may result in high alternating stresses. Analysis of a blade by itself, or for that matter a disc or cover by themselves, is easier. However, in reality, the impeller is a system that combines the blade, disc, and cover (impeller with shroud). The dynamic behavior of such a system becomes complex compared to that just for blades or just a disc. Understanding the dynamic behavior is important to rationalize fatigue failures and thus design a reliable impeller. The paper presents:
The results of the finite element analysis (FEA) of a simple impeller. These results help in the understanding of the behavior without the complexity of the results, thus paving the way to understand the behavior of similar complex systems. Specifically, it helps to:
- Rationalize the results of the system based on the results of blade alone and of disc alone.
- Describe a method to create an interference type diagram.
- Explain the results based on the diagram.
The results of the FE analysis for an impeller, and
A method that helps in drawing conclusion(s) about the possible resonance of an impeller. | en |