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September 25, 2023: Casey Harwood

September 25, 2023
4:00 p.m.
Room: 2150 Torgersen Hall
Casey Harwood, University of Iowa
Faculty Host: Dr. Christine Gilbert

"Fluid-Structure Interactions: Using Shape Sensing and System ID to Interpret Hydro-Structural Dynamics"

Abstract:  Fluid-structure interactions (FSI) can drive radical changes in the response behavior and stability of immersed structures, with outcomes ranging from the catastrophic structural failure of civil structures to the beneficial delay of stalled flow in high-lift aerospace control surfaces. Despite the ubiquity and importance of FSI in marine settings, direct observation of compliant structures is difficult to achieve. This talk will describe recent advances in the sensor design and modeling methodologies being used to study complex fluid-structure interaction problems. A robust, low-cost kinematic shape sensor (KSS) has been designed to provide 3D shape reconstruction with precision near that of photogrammetric methods, but without the need for optical access. When paired with robust parameter estimation algorithms, the KSS affords extremely accurate resolution of mode shapes and modal parameters for structures excited by ambient flow conditions. A multi-sensor “co-analysis” framework is introduced, wherein output-only structural analysis is executed concurrently with spectral proper orthogonal decomposition of a secondary videographic dataset, providing insight into synchronous fluid modes accompanying or exciting structural vibration. This FSI co-analysis is used to demonstrate modal coalescence, cavitation-induced vibration, and vortex lock-in of a compliant lifting surface in multi-phase flow. Applications of these new analytical techniques will be discussed, including the spatial model realization of immersed structures and the use of targeted fluid-structure resonances to achieve flow control

Bio:  Casey Harwood is an Assistant Professor in Mechanical Engineering and an Assistant Research Engineer with IIHR – Hydroscience and Engineering. Dr. Harwood received his M.S.E. and Ph.D in Naval Architecture and Marine Engineering from the University of Michigan and his B.S., also in Naval Architecture and Marine Engineering, from the Webb Institute in New York. At the University of Iowa, Dr. Harwood leads the Marine Science and Technology (MaST) lab, which performs research in experimental marine hydrodynamics. His current areas of focus include fluid-structure interactions, model-scale testing of marine vehicles, amphibious vehicle design and control, and surf-zone hydrodynamics. He is the recent recipient of an NSF CAREER award to experimentally study fluid-structure interactions for improved modeling and active control of fluid-loaded structures.