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Experimental study of the steady fluid-structure interaction of flexible hydrofoils

Citation

Zarruk, GA and Brandner, PA and Pearce, BW and Phillips, AW, Experimental study of the steady fluid-structure interaction of flexible hydrofoils, Journal of Fluids and Structures, 51 pp. 326-343. ISSN 0889-9746 (2014) [Refereed Article]

Copyright Statement

Copyright 2014 Elsevier

DOI: doi:10.1016/j.jfluidstructs.2014.09.009

Abstract

This paper presents results from an experimental study of the hydrodynamic and hydroelastic performance of six different flexible hydrofoils of similar geometry; four metal hydrofoils of stainless steel (SS) and aluminum (AL), and two composite hydrofoils of carbon-fiber reinforced plastic (CFRP). The two CFRP hydrofoils had differing layups, one with fibers at 0◦ and the other at 30◦ relative to the spanwise axis of the hydrofoil. All hydrofoil models have the same unswept trapezoidal planform of aspect ratio 3.33. Two section profiles were chosen, a standard NACA0009 (Type I) and a modified NACA0009 (Type II) with a thicker trailing edge for improved manufacture of CFRP hydrofoils. Hydrofoils were tested in a water tunnel mounted from a six-component force balance. Forces and deformations were measured at several chord-based Reynolds numbers up to Rec = 1.0  106 and incidences beyond stall. Hysteresis, force fluctuations, and the natural frequency of the hydrofoils in air and in water were also investigated. Pre-stall forces on the metal hydrofoils were observed to be Reynolds number dependent for low values but became independent at 0.8  106 and greater. Forces on the CFRP hydrofoils presented an increasing or decreasing lift slope for all Rec depending on the orientation of the carbon unidirectional layers. The change in loading pattern is due to the coupled bend-twist deformation experienced by the hydrofoils under hydrodynamic loading. Forces and deflections in the Type I hydrofoils were observed to be stable up to stall and non-dimensional tip deflections of were found to be independent of incidence and Rec. Type II metal hydrofoils had a mild Rec dependence, attributed to the blunt trailing edge, and Type II CFRP hydrofoils had a stronger incidence and Rec dependence. The natural frequency under stall conditions of all but one of the CFRP hydrofoils were in agreement with added mass and finite element analysis estimates. The disagreement was observed in the CFRP hydrofoil with layers aligned at 30◦ and is attributed to the complex behavior of the carbon layers and to the coupled bend-twist deformation experienced under hydrodynamic loading of the hydrofoil.

Item Details

Item Type:Refereed Article
Keywords:Fluid-structure interaction, hydrofoils, hydroelastic, composite
Research Division:Engineering
Research Group:Maritime Engineering
Research Field:Maritime Engineering not elsewhere classified
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in Engineering
Author:Zarruk, GA (Dr Gustavo Zarruk Serrano)
Author:Brandner, PA (Associate Professor Paul Brandner)
Author:Pearce, BW (Dr Bryce Pearce)
ID Code:95640
Year Published:2014
Web of Science® Times Cited:4
Deposited By:NC Maritime Engineering and Hydrodynamics
Deposited On:2014-10-06
Last Modified:2017-11-03
Downloads:0

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