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

Experimental Investigation of Solitary Wave Evolution Over a 3D Submarine Topography

1

Haocheng Lu1, Qian Wang1, Changze Zhao1, Philip L.-F. Liu2, Hua Liu1*

MOE Key Laboratory of Hydrodynamics, School of NAOCE, Shanghai Jiao Tong University, Shanghai, China
2
National University of Singapore, Singapore

ABSTRACTmeasured the run-up of solitary wave on planar beaches with different
slope, Liu and Al-Banaa (2004) on vertical walls, Monaghan et al(2004) on piecewise linear beaches, and Liu et al (1995) on idealized
islands or spatially varying topography. The evolution and runup of a
train of solitary waves on a uniform beach were investigatedexperimentally and numerically by Wu et al (2021), Rong et al (2016),and Wu et al (2015). These experiments have helped researchers tounderstand and validate numerical models of 2D wave evolution or runup.

The propagation and evolution of solitary waves on a 3D submarine
topography are investigated experimentally with wave gaugemeasurements, and acoustic Doppler velocimeter (ADV) velocity
measurements. The contour map of the submarine 3D topography canbe viewed as a slope composed of a series of circles studied by Whalin(1971). The arrival time of wave crest, the wave amplitude anddeformation, and the velocity of water particles are analyzed. It turns
out that the 3D topography has a significant effect on the wave
amplitude and deformation of solitary waves but no obvious influenceon the arrival time of wave crest. The distribution of velocity reveals
the convergence of the flow and the generation of turbulence. The
experimental results can be used as a benchmark for further validating
3D numerical models of breaking waves and provide more informationin understanding the complex mechanism of transformation of asolitary wave propagating over the 3D submarine topography.

In studying wave propagation over a 3D topography, Whalin (1971)
conducted a set of experiments on the propagation of regular waves,and showed that linear refraction theory was not suitable for describing
the wave transformation problem even for non-breaking waves. His
experimental results had been used as benchmark data in many
theoretical studies, such as studying a new form of the Boussinesq
equations with improved linear dispersion characteristics (Madsen et al,1992), and studying a time-dependent numerical model for extended
Boussinesq equations (Wei & Kirby, 1995; Chen & Liu, 1995). In
Whalin (1971)’s experiments, the velocity field was not measured.

KEY WORDS: wave evolution; 3D submarine topography; solitary
wave; experiment benchmark.

With the progress of experimental and observation equipment, moreexperiments have been carried out on solitary wave propagation andevolution over a 3D topography. Lynett et al (2010) conducted anexperimental survey on the 3D turbulence and kinematic characteristics
caused by breaking solitary wave. In the experiment, they used visualobservations, wave gauge measurements and acoustic Doppler
velocimeter (ADV) velocity measurements. Their topography wascomposed of a deep water region followed by a shallow shelf via a
relatively steep slope. They further refined their results later (Lynett etal, 2019), and concluded that nonlinear long-wave transformation overirregular topography can lead to a highly complex nearshore wave field.

INTRODUCTION
When ocean wave propagates to nearshore area, many phenomena suchas refraction, shoaling, breaking etc. occur as the submarine topographychanges. Because of the complexity of physical processes involved, nosimple and accurate theoretical method is capable to predict them.
Meanwhile, solitary wave, as a typical theoretical model of shallow
water long wave, is often used for simulating tsunami or nearshore longwave (Lin et al, 2004). Therefore, high quality experimental data on theevolution of a solitary wave over a 3D submarine topography can be
helpful in understanding the interaction between tsunami waves andnearshore topography.
Many two-dimensional studies on the evolution of solitary waves in thenearshore region have been reported and they have mostly focused on
the run-up. Synolakis(1987), Gedik et al. (2005), and Hsiao et al. (2008)

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In this paper, we carried out a new set of experiments using the scaled
Whalin’s topography. The transformation of solitary waves withdifferent wave amplitude is studied. Wave gauge measurements andADV measurements are obtained to analyze the arrival time of wave
crest, the wave amplitude and deformation, and the velocity of water