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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

Experimental study of wave transformation characteristics under effects of varying shallow water
Wei Lia,b Tingqiu Lia,b Zuyuan Liu Chaoyan Huang,a,b Qiu Jin
b,cWilliam Geraint Priceb,c Pandeli Temarelb,c Dominic Hudson
a,ba,cSchool of Transportation, Wuhan University of Technology(WUT), Wuhan, Hubei, Chinab
WUT-UoS High Performance Ship Technology Joint Centre, Wuhan, Hubei, ChinacUniversity of Southampton, Southampton, UK

through model test, and gave the corresponding calculation formula.
HSIAO(2008) proposed a prediction model of wave height climbing andheight by using nonlinear least squares regression based on theexperimental study of wave propagation along a gentle slope with a slopeof 1:60. Zhu(2017) conducted an experiment on wave climbing on a twolayer slope with a slope of 1:15, studied the influence of wave direction
Angle and wave steepness on climbing, and revised the wave height
formula with wave depth varying along the path through experimental
data results. Liu(2017) obtained high-resolution wave data in time andspace through wave flume wave creation experiment using image
method, and revealed the mechanism effect of incident waves withdifferent periods on the enhancement and weakening of sub-gravity
waves under the effect of shallow water. Peng(2018) conducted anexperimental study on the propagation and climbing of solitary waves
along a slope platform with a slope of 1:20. Based on the experimental
results, he proposed an empirical formula for the climbing of threesolitary waves with equal amplitude on a gentle slope. Yao(2018)
conducted an experimental study on wave height along a steep slope of
1:6, and proposed an empirical formula for wave height along a steep
slope. Wei(2021) pointed out the defects of the standard formula,modified and fitted the calculation formula and applicable scope, andobtained the calculation method of climbing wave height of strong
nonlinear regular waves through mathematical model tests and physicalmodel tests on three slopes with different gradients. However, due to theexperimental equipment and conditions (such as the length, width andpush amplitude of the wave tank), there are still few experimental studies
on the shallow water effect of waves on long gentle slope and related
wave height measurement. In the real sea, the slope of the continental
shelf adjacent to the continental slope is usually less than 7°, so theshallow sea area often presents the characteristics of very flat. The
maximum slope to the sea can be more than 20°.The previous studies aremainly focused on relatively gentle slope. In order to more accurately
simulate the near-shore deformation effect of waves in the ocean, it isnecessary to carry out experimental studies with larger gradients. Theslope adopted in this paper is a relatively steep slope with a slope ratioof 1:3.

ABSTRACTIn this paper, the variation characteristics of wave propagation on a slope
are studied by model experiments. The experimental data are analysedand compared with the analytical solution to generate the wave heightnarrow band graph. On this basis, the wave variation law and theintensity of the shallow water effect at different locations on the slope
platform are studied for different periods, wave height and highincidence parameters. The results show that the experiments have good
repeatability and small errors. The waves propagate and evolve on a 1:3
slope. The effect of shallow water variation is almost negligible at 1/4
length of slope. At 2/5 of the slope length, the shallow water effectgradually starts to appear. At the same time, the period of the wave risingfrom the trough to the crest becomes shorter and the period of the wave
falling from the crest to the trough becomes larger. At slope length 3/4,
the wave deformation under the effect of changing shallow water
increases sharply, leading to further shortening of the period from thetrough to the crest and further increase of the period from the crest to thetrough.

KEY WORDS: non-uniform water depth; shallow water effects;
sloping-bottom platform; experimental
narrowband graphs; wave breaking

research;wave

heightINTRODUCTION
A series of complex phenomena such as shallow, refraction, diffraction,reflection, floor friction energy dissipation and breakage occur whenwaves travel from deep sea to near-shore with the influence of complex
terrain, obstacles on the sea bottom. Free surface flow with large wave
deformation, run-up and wave breaking is a classical complex problem
in ocean engineering. It becomes more complex if the interactive
dynamics between the sea bottom and the free surface is required to beconsidered. Therefore, the physical model test method is still a main tool
to investigate the mechanism underlying the wave propagation.
Zhang(1989) studied the influence of water depth on wave height onslope, proposed the formation condition of maximum wave height3787