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

Research on the Influence of Seabed on the Hydrodynamic Performance of the Underwater Vehicle
Yu Guo1, Peng Li*1,2, Hongde Qin1, Zhiyuan Jiang1
1 State Key Laboratory of Autonomous Underwater Vehicle, Harbin Engineering University 2 Yantai Research Institute and Graduate School, Harbin

Engineering University
1Harbin, Heilongjiang, China 2 Yantai, Shandong, Chinadistance” based on CFD method. Zhu (2012) and Du (2014) obtained
the critical distance of the UV which is not affected by the seabed byusing model test and CFD method respectively. Korol (2016)
numerically simulated AUV zero-angle of attack towing test based on
CFD method, and further improved the calculation results on previousbasis. Chen (2017) used ANSYS-AQWA software to calculate theadded mass of the submarine helicopter and obtained the linear
relationship between the added mass and the near-seabed distance. For
the complex seabed topography, Li (2012) used dynamic mesh method
to simulate the process of human occupied vehicle dynamic approach toseabed structures. Liu (2015) selected four typical seabed topography toanalyze the influence of different seabed topography on the UV by
using the dynamic mesh method. Yan (2016) studied the variation of
the UV hydrodynamic performance with the inclination and horizontal
length of the front lower slope based on CFD method. Mitra (2020)
used both model test and CFD method to study the hydrodynamic
characteristics of the UV on inclined river bed topography withdifferent Reynolds numbers.
The purpose of the paper is to forecast the evolution of thehydrodynamic parameters of the UV when navigating near the seabed.
Based on the analysis of the influence of the flat seabed on the UV,
common submarine sand waves topography is selected to investigate
the evolution of the drag coefficients and lift coefficients of the UV in
the process of navigating over submarine sand waves.

ABSTRACT
When an Underwater Vehicle (UV) moves close to the seabed, theinteraction of flow field between the UV and the seabed adversely
affects its operation safety. In order to predict the evolution of thehydrodynamic performance of the UV and flow field characteristics inthe vicinity of UV under the influence of the seabed, in the paper, theflow field near the seabed was numerically simulated using
computational fluid dynamics (CFD) method. The influence of the flat
seabed topography on the UV is first studied, and the submarine sandwaves topography were further analyzed. The results show that within acertain range from the seabed, the drag and attractive force of the UV
will increase, and continuous changes of seabed topography has asignificant influence on the UV.

KEY WORDS: Underwater vehicle; hydrodynamic performance;
flow characteristics; computational fluid dynamics.

INTRODUCTION
With the rapid development of science and technology and marine
equipment, human exploration of oceans has gradually stepped fromshallow to deep. UVs have been widely used in the mapping of seabedtopography and geomorphology, seabed tracking and detection,submarine oil and gas pipeline inspection, submarine cable burying andmaintenance, etc. (Panda et al., 2021). However, when the UV operates
near the seabed, compared with the unbounded domain, the seabed willchange the flow field around the UV, which will interfere with thehydrodynamic performance of the UV and affect the operation safety(Korol et al., 2016). In addition, the seabed topography is complex, thechange of topography will have a more significant and unpredictableinfluence on the safety of the UV navigating near the seabed. In thecase of insufficient research on the hydrodynamic interference of theseabed to UVs at present, in order to avoid the risk of collision, in theuses of UVs mentioned above, usually they are limited to a certain
distance from the seabed, which affects the operation accuracy.
Therefore, for UVs operating close to the seabed, it is of interest toinvestigate the influence of the seabed on the hydrodynamic
performance of them.
At present, some studies have been carried out on the influence ofthe seabed on UVs. For the flat seabed topography, Wu (2005)
calculated a good linear relationship between part of hydrodynamic
parameters of submarine and “reciprocal of dimensionless near-seabed

NUMERICAL METHODOLOGY
In the paper, STAR-CCM+ software is used for numericalsimulation, Reynolds-Averaged Navier-Stokes (RANS) equations aresolved based on Finite Volume Method (FVM), and overset meshmethod is used to simulate the navigation of the UV.

Governing equations and turbulence model
Since the hydrodynamic characteristics of the UV is studied in thepaper, the basic governing equations include mass conservation andmomentum conservation equations, and momentum conservation
equation is also called Navier-Stokes equation. RANS equations obtainthe time-averaged mass conservation equation and momentum
conservation equation:
ui=0(1)xi(  ui ) (  ui u j )p +=−+(−  uiu j ) +  2 uitxj
xi x j

1051(2)