Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Numerical Investigation on Fluid-Structure Interaction Dynamics of a Flexible Marine Propeller
Bowen Maa, Guoxiang Donga, Wenyong Tangb and Yunlong Jina
aState Key Laboratory of Navigation & Safety Technology, Shanghai Ship and Shipping Research Institute, Shanghai, China
bState Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai, Chinamay be subject to periodic transient responses due to hydrodynamic
loads and centrifugal forces, resulting in amplified stress, distortion oreven vibrational resonance. As a conventional engineering solution forpropeller design and analysis, the blades are assumed perfectly rigid,
which allows for the separate calculation of hydrodynamic forces and theassociated structural responses (Atkinson, 1973; Genalis, 1970; Ma,1974). In this manner, hydroelastic behaviours of propellers can bedetermined by the undeformed blade geometry without consideration offluid-structure interaction.

ABSTRACT
Marine propellers may experience hydro-elastic responses due to thefluid-structure interaction (FSI) between flow and blades, which worsens
the hydrodynamic performance, reliability and radiation of noise. The
present study aims to numerically investigate hydro-elastic
characteristics of a marine propeller and understand the significance of
one-way and two-way coupled FSI in the propeller performance anddynamic behaviour. For this purpose, computational fluid dynamics(CFD) and finite element method (FEM) are combined to simulatehydrodynamics and structural responses of a propeller for various
advance ratios. Three-dimensional modelling of the propeller geometryis performed via coordinate transformation formulae, where geometricalcurves are obtained based on two-dimensional blade profiles and design
parameters. For a rigid propeller, the numerical model is validated bycomparing uncoupled steady-state results with open-water test data
available for the selected propeller in terms of thrust coefficient, torquecoefficient and efficiency. The blades can be considered as cantileverlike structures undergoing hydrodynamic load and centrifugal force,
while the structural deformation may influence the flow field. By
carrying out transient simulations via one- and two-way FSI methods,
hydrodynamic performance and quasi-static blade responses of ametallic propeller under a uniform flow are evaluated. The results showthat the propeller blade deformation is decreased with advance ratios dueto the reduced thrust and torque. Through comparing the CFD steadystate and FSI results, the two-way coupling effects on the hydrodynamics
and structural dynamics of the propeller are assessed.

To consider the coupling effects, Atkinson and Glover (1988) applied an
iterative procedure accounting for the influence of blade deformation on
the fluid pressure by combining a vortex-lattice method (VLM) and afinite-element method (FEM). Lin and Lin (1996) also considered aVLM/FEM coupled approach to investigate hydroelastic effects on amarine propeller in steady flow. The fluid and structure models arecoupled and solved in an iterative manner with consideration ofgeometrical nonlinearity. They reported that the hydrodynamicperformance is influenced by the structural deflections. By assessing theeffects of blade thickness on hydrodynamic performance, it is revealed
that thinner blades lead to greater deflection, thrust and torque of thepropeller. Hydro-elastic effects on propeller blades in steady flow wasalso studied by Georgiev and Ikehata (1998), where a FEM and boundary
element method (BEM) was combined to analyse the relationshipbetween structural deformation and hydrodynamic characteristics. They
remarked that pitch variation due to the deflection significantly affect thepropeller hydrodynamic performance. By using a BEM/FEM coupling
method, Young (2007) carried out a time-dependent hydro-elastic
analysis of cavitating propellers. The structural responses owing tohydrodynamic loads are evaluated with consideration of fluid-structureinteraction. As an extended study, Young (2008) further investigated thefluid-structure interaction of flexible composite propellers in
subcavitating and caveating flows. It is addressed that fluid-structureinteraction are important in prediction of hydrodynamic performance,
blade deformation and structural natural frequency.

KEY WORDS: fluid-structure interaction; one-way coupling; twoway coupling; marine propeller; CFD; hydrodynamics.

INTRODUCTION
A marine propeller is a fan-like structure, propelling the ship throughconverting the rotational motion into thrust by generating a pressure
difference in the surrounding field. Blades are the main part of thepropeller and most concerned for the preliminary design. To optimizeefficiency, propellers can be designed differently in terms of various
blade factors, such as number, material and geometry, depending on thespeed and manoeuvring requirements of the vessel. However, blades

The above potential-based methods (VLM or BEM) for obtaininghydrodynamic loads are limited to an assumption of inviscid flows. Fora more detailed unsteady fluid analysis, computational fluid dynamics(CFD) can be used. By applying a CFD/FEM coupled method, He et al.

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