Xiaomeng Tong, Alan Palazzolo and Junho Suh's research paper titled ‘Rotordynamic Morton Effect Simulation with Transient, Thermal Shaft Bow’ was awarded the American Society of Mechanical Engineers (ASME) Journal of Tribology best paper award. Drs. Tong, Palazzolo and Suh were presented with award plaques at the STLE Tribology Frontiers Conference which was held in Chicago, Illinois on November 13-15, 2016.
The Morton Effect is characterized by an asymmetric journal temperature distribution, slowly varying thermal bow and intolerable synchronous vibration levels. The conventional mass imbalance model is replaced by a more accurate thermal shaft bow model. Rotor permanent bow and disk skew are synchronous excitation sources, and are incorporated in the dynamic model to investigate their influence on the Morton effect. A hybrid beam/solid element finite element shaft model is utilized to provide improved accuracy for predicting the rotor thermal bow and expansion, with practical computation time. Morton Effect is shown to be induced by initial shaft bow and disk skew. The conventional mass imbalance approach is shown to have some limitations.
Junho Suh and Alan Palazzolo’s research paper titled ‘Three-Dimensional Thermodynamic Morton Effect Simulation Part I & Part II’ was awarded the best American Society of Mechanical Engineers (ASME) Journal of Tribology paper award for 2014. Suh and Palazzolo were presented with award plaques at the Frontier of Tribology Conference that was held in Chicago, Illinois on October 27, 2014.
The paper develops modelling and simulation methodology for preventing the Morton Effect (ME). The ME is increasingly observed on high performance turbomachinery operating in petrochemical and power plants. The ME originates in fluid film bearings which support the high rpm shaft of a turbomachine. Under appropriate conditions the ME gives rise to increasing mass unbalance, causing large centrifugal forces and ensuing vibration of the shaft. Industry standards such as API, ISO, MIL highly discourage operation when vibration levels exceed allowable values, thus the machine and its accompanying manufacturing process are shut down. This may result in the loss of millions of dollars of product and in related lawsuits. The methodology is multiphysics based, combining intricate thermal and flow simulation of the bearing's lubricant oil film coupled with elastic deformation, conduction- convection thermal simulations of the bearings, and vibration simulations of the shaft. The presence of very long and very short time constant phenomena in the ME presents a formidable computational challenge that is treated in an efficient and effective manner. This research is funded by the Turbomachinery Research Consortium (TRC) of the Texas A&M Turbomachinery Laboratory.
Dr. Suh completed his PhD at TAMU and is presently a Senior Researcher at the Korea Railroad Research Institute. He continues his bearing related and rotordynamic research. Dr. Palazzolo is a professor in the Department of Mechanical Engineering at Texas A&M and an ASME Fellow. His research interests include rotor-dynamics, magnetic bearings, active vibration control, fluid film bearings, vibrations, finite elements, seal and impeller leakage flow, energy storage flywheels, direct fuel injectors and other electromechanical systems.