Laboratory observations of wave evolution, modulation and blocking due to spatially varying opposing currents

Ma, Yuxiang; Dong, Guohai; Perlin, Marc; Ma, Xiaozhou; Wang, Guanchao; Xu, Jian

doi:10.1017/s0022112010002880

Cited by 33 publications

(41 citation statements)

References 27 publications

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“…Wave propagation against nonuniform opposing currents was recently investigated in experiments conducted by Ma et al (2010). Results confirm that opposing current not only increases the wave steepness but also shortens the wave energy transfer time and accelerates the development of sideband instability.…”

Section: V Shugan Et Al: An Analytical Model Of the Evolution Ofmentioning

confidence: 88%

“…The interaction of steep surface waves with strong adverse current under wave-blocking conditions including wave breaking effects is presented in Sect. (2002) and Ma et al (2010). Section 5 summarizes our final conclusions and discussion.…”

Section: V Shugan Et Al: An Analytical Model Of the Evolution Ofmentioning

confidence: 93%

“…Nevertheless, the experimental results of Chavla and Kirby (2002) and Ma et al (2010) on the modulation instability under the influence of adverse current show that energy spectrum is mostly concentrated in the main triad of waves and high-frequency discretized energy spreading is depressed due to the short-wave blocking by the strong enough adverse current. Higher side band modes have also prevailed energy loss during wave breaking (Tulin and Waseda, 1999).…”

Section: V Shugan Et Al: An Analytical Model Of the Evolution Ofmentioning

confidence: 99%

“…3c). We also performed numerical simulations for the boundary conditions and the form of the variable current obtained in two series of experiments conducted by Chavla and Kirby (2002) and Ma et al (2010).…”

Section: Wave Propagation Under the Blocking Conditions Of Strong Advmentioning

confidence: 99%

“…The phenomenon can be considered the discrete evolution of the spectrum of the surface wave under the influence of nonuniform adverse current. Experiments conducted by Kirby (1998, 2002) and Ma et al (2010) revealed that sufficiently steep surface waves overpass the barrier of strong opposing current on the lower resonant Benjamin-Feir sideband. These reports highlight that the frequency step of a discrete downshift coincides with the frequency step of modulation instability; i.e., after some distance of wave run, the maximum of the wave spectrum shifts in frequency to the lower sideband.…”

Section: Introductionmentioning

confidence: 99%

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An analytical model of the evolution of a Stokes wave and its two Benjamin–Feir sidebands on nonuniform unidirectional current

Shugan

Hwung

Yang

2015

Nonlin. Processes Geophys.

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Abstract. An analytical weakly nonlinear model of the Benjamin-Feir instability of a Stokes wave on nonuniform unidirectional current is presented. The model describes evolution of a Stokes wave and its two main sidebands propagating on a slowly varying steady current. In contrast to the models based on versions of the cubic Schrödinger equation, the current variations could be strong, which allows us to examine the blockage and consider substantial variations of the wave numbers and frequencies of interacting waves. The spatial scale of the current variation is assumed to have the same order as the spatial scale of the Benjamin-Feir (BF) instability. The model includes wave action conservation law and nonlinear dispersion relation for each of the wave's triad. The effect of nonuniform current, apart from linear transformation, is in the detuning of the resonant interactions, which strongly affects the nonlinear evolution of the system.The modulation instability of Stokes waves in nonuniform moving media has special properties. Interaction with countercurrent accelerates the growth of sideband modes on a short spatial scale. An increase in initial wave steepness intensifies the wave energy exchange accompanied by wave breaking dissipation, resulting in asymmetry of sideband modes and a frequency downshift with an energy transfer jump to the lower sideband mode, and depresses the higher sideband and carrier wave. Nonlinear waves may even overpass the blocking barrier produced by strong adverse current. The frequency downshift of the energy peak is permanent and the system does not revert to its initial state. We find reasonable correspondence between the results of model simulations and available experimental results for wave interaction with blocking opposing current. Large transient or freak waves with amplitude and steepness several times those of normal waves may form during temporal nonlinear focusing of the waves accompanied by energy income from sufficiently strong opposing current. We employ the model for the estimation of the maximum amplification of wave amplitudes as a function of opposing current value and compare the result obtained with recently published experimental results and modeling results obtained with the nonlinear Schrödinger equation.

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Section: V Shugan Et Al: An Analytical Model Of the Evolution Ofmentioning

confidence: 88%

Section: V Shugan Et Al: An Analytical Model Of the Evolution Ofmentioning

confidence: 93%

Section: V Shugan Et Al: An Analytical Model Of the Evolution Ofmentioning

confidence: 99%

Section: Wave Propagation Under the Blocking Conditions Of Strong Advmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

An analytical model of the evolution of a Stokes wave and its two Benjamin–Feir sidebands on nonuniform unidirectional current

Shugan

Hwung

Yang

2015

Nonlin. Processes Geophys.

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Development of bedforms due to waves blocked by a counter current

Chatterjee

Ghosh

Mazumder

et al. 2019

Earth Surf Processes Landf

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Experiments are conducted in a laboratory flume on the propagation of a surface wave against unidirectional flow with a sediment bed. This article presents the spatial variation of bedforms induced by the wave‐blocking phenomenon by a suitably tuned uniform fluid flow and a counter‐propagating wave. The occurrence of wave‐blocking is confirmed by finding a critical wave frequency in a particular flow discharge in which the waves are effectively blocked and is established using the linear dispersion relation. The purpose of this work is to identify wave‐blocking and its influence on the development of bedforms over the sediment bed. Interestingly bedform signatures are observed at a transition of bedforms in three zones, with asymmetric ripples having a steeper slope downstream face induced by the incoming current, followed by flat sand bars beneath the wave‐blocking zone and more symmetric ripples below the wave‐dominated region at the downstream. This phenomenon suggests that the sediment bed is segmented into three different regions of bed geometry along the flow. The deviations of mean flows, Reynolds stresses, turbulent kinetic energy, and power spectral density due to the wave‐blocking phenomenon are presented along the non‐uniform flow over sediment bed. The bottom shear stress, bed roughness and stochastic nature of the bedform features are also discussed. The results are of relevance to engineers and geoscientists concerned with contemporary process as well as those interested in the interpretation of palaeoenvironmental conditions from fossil bedforms. © 2019 John Wiley & Sons, Ltd.

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