Understanding Design Parameters That Affect Thermal Stability of High-Speed Turbo Machinery (Also Known As the Morton Effect)

At present, there are no commercially available codes in industry that have been found to be accurate, reliable and consistent enough to predict both the onset of the Morton Effect and a rotor’s response to the Morton Effect to be used as a design tool with hard acceptance criteria in the upfront design of turbomachinery. The available tools have however shown the ability to predict the proper trends associated with many changes made to help enhance machine stability when the Morton Effect is recognized. The Morton Effect refers to synchronous rotor instability due to non-uniform heating of shaft journals. The industry’s inability to reliably and consistently predict this phenomenon has caused both plant start-up delays and shutdowns due to machinery vibration. The multiple case studies that will be presented assess this problem and summarize the solutions that were developed, tested and ultimately implemented to address the Morton Effect.