Longshore current instability is important to nearshore hydrodynamic and sediment transport. This paper investigates the longshore current instability growth model based experimental data with different velocity profi...Longshore current instability is important to nearshore hydrodynamic and sediment transport. This paper investigates the longshore current instability growth model based experimental data with different velocity profiles of slopes1:100 and 1:40 by adopting a linear shear instability model with the bottom friction effects. The results show that:(1)Only backshear mode exists in the instability of longshore current for slope 1:40 and frontshear and backshear modes may exist slope 1:100.(2) The peaks of linear instability growth mode for slope 1:100 correspond to three cases: the dominant peak is formed by the joint action of both frontshear and backshear, or by backshear alone without the existence of the smaller peak or formed by either the frontshear or backshear.(3) Bottom friction can decrease the corresponding unstable growth rate but it cannot change the unstable fluctuation period. The results of fluctuation period, wavelength and spatial variation obtained by the analysis of linear shear instability are in good agreement with experimental results.展开更多
Crescent waves often observed on the sea surface are unusual wave pattern induced by the instability of Stokes wave.The paper presents the experimental results of the wave field around a circular cylinder generated by...Crescent waves often observed on the sea surface are unusual wave pattern induced by the instability of Stokes wave.The paper presents the experimental results of the wave field around a circular cylinder generated by the diffraction of crescent wave in order to examine the difference of diffracted crescent waves from the commonly-used diffracted Stokes waves. The results show that with the existence of the cylinder, the crescent wave pattern can still get fully developed, and with the presence of this type of wave pattern, the symmetry breaking of the wave amplitude distribution occurs and there are extra wave components at the frequencies of 0.5 ω;, 1.5ω;and 2.5ω;（ω;is the frequency of Stokes waves） appearing in the wave amplitude spectrum.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51879237 and 11602222)the Research Fund of Zhejiang Ocean University(Grant No.11185010817)+2 种基金Zhejiang Provincial Natural Science Foundation of China(Grant No.LR16E090002)the Fundamental Research Funds for the Central Universities(Grant No.2018QNA4041)the Project of Research on structure properties of framed seawall along the Oujiang River in Lucheng District of Wenzhou City
文摘Longshore current instability is important to nearshore hydrodynamic and sediment transport. This paper investigates the longshore current instability growth model based experimental data with different velocity profiles of slopes1:100 and 1:40 by adopting a linear shear instability model with the bottom friction effects. The results show that:(1)Only backshear mode exists in the instability of longshore current for slope 1:40 and frontshear and backshear modes may exist slope 1:100.(2) The peaks of linear instability growth mode for slope 1:100 correspond to three cases: the dominant peak is formed by the joint action of both frontshear and backshear, or by backshear alone without the existence of the smaller peak or formed by either the frontshear or backshear.(3) Bottom friction can decrease the corresponding unstable growth rate but it cannot change the unstable fluctuation period. The results of fluctuation period, wavelength and spatial variation obtained by the analysis of linear shear instability are in good agreement with experimental results.
基金financially supported by the National Natural Science Fundation of China(Grant No.51879237)the Research Start Fund of Zhejiang Ocean University(Grant No.11185010817)
文摘Crescent waves often observed on the sea surface are unusual wave pattern induced by the instability of Stokes wave.The paper presents the experimental results of the wave field around a circular cylinder generated by the diffraction of crescent wave in order to examine the difference of diffracted crescent waves from the commonly-used diffracted Stokes waves. The results show that with the existence of the cylinder, the crescent wave pattern can still get fully developed, and with the presence of this type of wave pattern, the symmetry breaking of the wave amplitude distribution occurs and there are extra wave components at the frequencies of 0.5 ω;, 1.5ω;and 2.5ω;（ω;is the frequency of Stokes waves） appearing in the wave amplitude spectrum.
