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

Interaction of a Propeller with Ship Flows by the RANS over Overset Meshes
Ziping Wanga,b Tingqiu Lia,b Zuyuan Liua,b Qiu Jinb,cWilliam Geraint Priceb,c Pandeli Temarelb,c Dominic Hudsonb,caSchool of Naval Architecture, Ocean and Energy Power Engineering, Wuhan University of Technology, Wuhan, Hubei, China
bKey Laboratory of High Performance Ship Technology(Wuhan University of Technology), Wuhan, Hubei, China
cUniversuty of Southampton, Southampton, UKThe turning rudder adds more complexity to the system. The changes ofrudder attitude lead to the change of ship motions, which further affectthe flow field around the ship hull and the propeller. The interactions
between the ship hull, the propeller and the rudder are coupled, andignoring one of these factors eventually affects the simulation results. In
addition, the high-speed rotation of the propeller generates cavitation andcomplex flow field at the rear of the hull, which will also bring
unprecedented challenges to the study of such problems.

ABSTRACTThe problem for interactional flows between the ship hull and thepropeller is studied by computational fluid dynamics (CFD) simulatorswith the RANS-based computational model. In this paper, we mainly
emphasize the modelling of the propeller, by introduction of a multiplereference frame (MRF) approach and an overset mesh method.
Importantly, the effects of a free-surface on the interactions are taken
into account by the VOF method. By comparison with the experimental
data for the standard model KRISO container ship (KCS), bothtechnologies for the treatment of the propeller can capture its movementin open water like the ship resistance and self-propulsion, including thedistributions of the pressure on the hull surface, streamline at the sternand the ship boundary layer caused by propeller suction. Interestingly,
the results of the thrust and torque agree well with such both approaches,
although the hull resistance is overestimated by the MRF method,resulting in substantial calculation errors of the prediction of the selfpropulsion coefficients. Within the framework of these techniques, theMRF method trends to be higher efficiency in computations but
conversely for the overset mesh method there exists higher accuracy. Byvisualization of the motions that describe the physics of the interaction
between the ship hull and propeller, it has been shown that the simulators
can capture most of the significant features in ship-propeller interactions
with a free-surface.

The importance of the interactions between the ship hull, the propeller
and the rudder has long been recognized. As a powerful investigation
tool, experimental fluid dynamics (EFD) has been used for decades (Kinet al., 2001; Lee et al., 2003). Whereas experimental techniques are welldeveloped, detailed physical description and accurate modelling are stilllack (Van et al., 2006). An alternative method is to use computational
fluid dynamics (CFD) tools to predict the interactions. In the numericalinvestigations, the main problem is to well resolve the high-speed
rotation of the propeller.
Two main set of methods to dealing with the rotating propeller are bodyforce methods and ship/propeller holistic modelling methods. The bodyforce methods are widely used in self-propulsion since it is relatively
simple to model and high in computational efficiency (Chen et al., 2003;
Wang et al., 2021; Guo et al., 2020). But only a very rough approximatedprediction is given in this method when it comes to the influence of thechange of the propeller geometry on the ship flow field. The accuracy ofthe body force method is limited in the flow field in the area where thepropeller disk is located.

KEY WORDS: Self-propulsion; the MRF Method; the Overset Meshes;
Free-surface.

INTRODUCTION

Recently, ship/propeller holistic modelling methods that resolve themotion of the rotating propeller has become another powerful tool tointeractions between the ship hull, the propeller and the rudder. Althoughhigher cost in computational time, ship/propeller holistic modelling
methods with discretized rotating propeller allow a detailed investigationof the complex flow field generated around and behind the propeller.
Base on the mesh generation for the propeller, the ship/propeller holistic

The interaction among ship, propeller and rudder is one of the mostcomplex ship hydrodynamic problems. The flow around the propeller
behind a moving ship is completely different from that in open waterwith a uniform inlet flow condition. At the same time, velocity
distribution of flow around the hull is affected by the rotating propeller.

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