Abstract
A test rig has been developed at the Waterpower Laboratory of the Norwegian University of Science and Technology to conduct an in-depth investigation of flow-related phenomena and fluid-structure interaction, with the focus towards hydrodynamic damping, for a circular hydrofoil cascade configuration. The rig’s design enables the analysis of hydrodynamic damping by utilizing sensors on the structure and optical access to evaluate wake flow dynamics through advanced techniques such as Particle Image Velocimetry and Laser Doppler Velocimetry. The paper presents the rig’s capabilities and a comparison of the results of both experimental and numerical modal analyses to identify the cascade’s natural frequencies and main mode shapes, as preliminary step before future hydrodynamic damping measurements. This paper lays the foundation for further investigations into hydrodynamic damping measurements and contributes to the characterization of the circular hydrofoil cascade test rig. A comparative analysis of numerical modal methods as cyclical symmetry and a full-model approach has been conducted.