From Turbo to Toledo: Notre Dame graduate student shares research findings at leading international turbomachinery symposium

Author: Brett Beasley


Last semester, Notre Dame Turbomachinery Lab (NDTL) aerospace and mechanical engineering graduate student Val Hernley presented research findings at the International Symposium on Unsteady Aerodynamics, Aeroacoustics, and Aeroelasticity of Turbomachines (ISUAAAT) in Toledo, Spain. First held in Paris in 1976, ISUAAAT is a premiere triennial scholarly event. This year’s conference featured presentations on the latest discoveries in flow-induced vibrations in turbomachinery, and the world’s leading experts in unsteady aerodynamics and aeromechanics were in attendance.

Hernley shared the results of aeromechanics experiments performed at the Notre Dame Turbomachinery Lab in collaboration with Doosan Enerbility. The experiments examined the cause of blade vibration at off-design conditions of a 1.5 stage power generation compressor. Detailed analysis of the experimental data revealed that unsteady pressure fluctuations inherent to the off-design aerodynamics were resonantly forcing the blades at their natural frequency. Hernley explained how the team identified this root cause so it can be mitigated in future designs.

Hernley’s presentation was well-received, and the results sparked discussions about the wide variety of different physical mechanisms that can cause vibration.

Scott Morris, professor of aerospace and mechanical engineering and director of the Institute for Flow Physics and Control (FlowPac), said, “The study of flow-induced vibrations is one of the most challenging and important fields of study in aerospace engineering. Ms. Hernley's work will certainly have a strong impact on the field by helping us to better understand cause and effect relationships that lead to unwanted vibration.”

Hernley said, “I appreciated the opportunity to discuss these topics face-to-face with leading experts in the field of turbomachinery aeromechanics. It didn’t hurt, either, that the conference was in a beautiful medieval city in Spain!”

To learn more about Notre Dame’s graduate program in Aerospace and Mechanical Engineering, visit

About the Notre Dame Turbomachinery Lab

NDTL is a University of Notre Dame and South Bend, Indiana-based research and development facility that combines the benefits of a vibrant academic research program with a mid-TRL development and validation test facility serving the aerospace and power generation industries. NDTL’s staff expertise includes internal and external aerodynamics, structural dynamics, instrumentation, combustion, computational fluid dynamics, acoustics, and tribology.


Brett Beasley / Writer and Editorial Program Manager

Notre Dame Research / University of Notre Dame / 574.631.8183 / @UNDResearch

About Notre Dame Research:

The University of Notre Dame is a private research and teaching university inspired by its Catholic mission. Located in South Bend, Indiana, its researchers are advancing human understanding through research, scholarship, education, and creative endeavor in order to be a repository for knowledge and a powerful means for doing good in the world. For more information, please see or @UNDResearch.