Kinematic Sensing and Parameter Estimation of Flexible Lifting Bodies in Multiphase flows
Abstract
The objective of this work is to support the on-line system identification of hydroelastically-active marine structures through thedevelopment of novel sensing and parameter estimation methods. Hydrofoils, propeller blades, and control surfaces experience large and often unsteady hydrodynamic forces. At the same time, such lifting surfaces are often relatively slender, and the increasinguse of composite materials necessitates closer scrutiny of the fluid-structure interactions (FSI) that can occur in all regimes of operation. Moreover, active control strategies may be used to mitigate potentially harmful instabilities, or even take advantage of FSI to delay or control the cavitating or ventilating flows around high-speed lifting surfaces. The pursuit of active control must be supported by simultaneous improvements in the sensing of flexible marine structures, as well as the on-line processing of measurements to extract meaningful insight into the dynamics (natural frequencies, damping ratios, and mode shapes) of marine lifting surfaces under changing flow conditions with limited optical access. The proposed work aims to improve upon the design and construction ofprior shape-sensing designs by the PI, which utilize low-cost resistive strain gauges on a removable spar to reconstruct the staticand dynamic deformations of a hydrofoil in both bending and twisting with high accuracy and minimal latency. We also propose to useestablished and modified parameter estimation methods to extract natural frequencies, damping ratios, mode shapes, and fluid-induced vibrations from input-output and output-only datasets. These methods, when used on-line enable meaningful co-analysis of fluid andstructural modes to predict, avoid, and/or control fluid-structure instabilities for improved safety, efficiency, and control of multi-phase flow regimes.Approved for Public Release
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 09, 2021
- Source ID
- N000142112542
Entities
People
- Casey Harwood
Organizations
- Office of Naval Research
- United States Navy
- University of Iowa