共查询到18条相似文献，搜索用时 109 毫秒
1.
Chen-Yuan CHEN John Rong-Chung HSU Ching-Feng KUO Hsin-Hsun CHEN Min-Hung CHENG 《中国海洋工程》2006,20(1):61-72
Laboratory experiments were conducted in a wave flume on internal solitary wave （ISW） of depression and elevation types propagating over a submarine ridge in semicircular/triangular shape. Tests were arranged in series for combinations of submarine ridges of different heights and ISW of different amplitudes. The resuhant wave motions were found differing from thee of surface gravity waves. In deeper water, where an ISW of depression-type prevailed, the process of wave breaking displayed downward motion with continuous eddy on the front face of the ridge followed by upward motion towards the apex of the obstacle. Experimental results also suggested that blockage parameter ξ could be applied to classify various degrees of ISW-ridge interaction, i.e., ξ 〈 0.5 for weak interaction, 0.5 〈 ξ 〈 0.7 for moderate interaction, and 0.7 〈 ξ for wave breaking. 相似文献
2.
Numerical modeling on the interaction of internal solitary wave with slope-shelf and modal analysis 总被引：1，自引：0，他引：1
On the basis of a nonhydrostatic numerical model,the interaction of internal solitary wave with slope-shelf was studied.The breaking and polarity transformation were analyzed.A "kink" structure,due to shoaling topography and higher nonlinear effect,was found to be generated by the leading wave before breaking.Coherent vortex shedding behind the leading wave was presented.The evolution characteristics of the modal structure were analyzed based on the empirical orthogonal function method.The modal structure was complicated due to the effect of the variable topography,especially when breaking occurred.In the performed experiments,the contributions to the total variance from higher mode jumped from no more than 20% to over 40%. 相似文献
3.
Wang Yongxue
Professor State Key Laboratory of Coastal Offshore Engineering Dalian University of Technology Dalian 《中国海洋工程》1995,(1)
- In this paper, the solitary wave deformation along a gentle slope and the impact pressure, on the wall are investigated experimentally and the results are compared with numerical results obtained based on the volume of fluid (VOF) method. The topography used in the experiment consists of three segments. The left segment is a 1:4 slope, the middle segment 1 :SO slope and the right segment a horizontal bed. Both the wave heights and breaking points obtained from numerical simulation and experiments are in good agreement. Numerical results give reasonable pressure distributions of breaking waves on the wall. 相似文献
4.
In the present paper, by introducing the effective wave elevation, we transform the extended ellip- tic mild-slope equation with bottom friction, wave breaking and steep or rapidly varying bottom topography to the simplest time-dependent hyperbolic equation. Based on this equation and the empirical nonlinear amplitude dispersion relation proposed by Li et al. (2003), the numerical scheme is established. Error analysis by Taylor expansion method shows that the numerical stability of the present model succeeds the merits in Song et al. (2007)’s model because of the introduced dissipation terms. For the purpose of verifying its performance on wave nonlinearity, rapidly vary- ing topography and wave breaking, the present model is applied to study: (1) wave refraction and diffraction over a submerged elliptic shoal on a slope (Berkhoff et al., 1982); (2) Bragg reflection of monochromatic waves from the sinusoidal ripples (Davies and Heathershaw, 1985); (3) wave transformation near a shore attached breakwater (Watanabe and Maruyama, 1986). Comparisons of the numerical solutions with the experimental or theoretical ones or with those of other models (REF/DIF model and FUNWAVE model) show good results, which indicate that the present model is capable of giving favorably predictions of wave refraction, diffraction, reflection, shoaling, bottom friction, breaking energy dissipation and weak nonlinearity in the near shore zone. 相似文献
5.
This paper studies the continuous evolution of breaking wave for the surface water waves propagating on a sloping beach. A Lagrangian asymptotic solution is derived. According to the solution coupled with the wave breaking criteria and the equations of water particles motion, the wave deformation and the continuous wave breaking processes for the progressive water waves propagating on a sloping bottom can be derived. A series of experiments are also conducted to compare with the theoretical solution. The results show that the present solution can reasonably describe the plunging or spilling wave breaking phenomenon. 相似文献
6.
A one-dimensional mixed-layer model, including a Mellor-Yamada level 2.5 turbulence closure scheme, was implemented to investigate the dynamical and thermal structures of the ocean surface mixed layer in the northern South China Sea. The turbulent kinetic energy released through wave breaking was incorporated into the model as a source of energy at the ocean surface, and the influence of the breaking waves on the mixed layer was studied. The numerical simulations show that the simulated SST is overestimated in summer without the breaking waves. However, the cooler SST is simulated when the effect of the breaking waves is considered, the corresponding discrepancy with the observed data decreases up to 20% and the MLD calculated averagely deepens 3.8 m. Owing to the wave-enhanced turbulence mixing in the summertime, the stratification at the bottom of the mixed layer was modified and the temperature gradient spread throughout the whole thermocline compared with the concentrated distribution without wave breaking. 相似文献
7.
Dong Guohai Li Yucheng Wang Yongxue
Lecturer Doctor Dalian University of Technology Dalian
Professor Dalian University of Technology Dalian 《中国海洋工程》1995,(1)
- A large amount of experimental analysis and systematical theoretical calculation has been done by the authors to solve the problem of wave transformation and breaking, considering the effect of both current and topography, but only the wave energy loss due to spilling breaker in the surf zone has been discussed in this paper. Based on test result analysis and calculation with the Stream Function Wave Theory, the wave velocity field at breaking points has been obtained, and it is used to calculate the wave heights after breaking by the VOF (Volume of Fluid) method, in which the governing equations are continuity equation and Navier-Stokes Equation for imcompressible fluids. In the present paper, the improved VOF technique is used to calculate the wave heights of stable regular waves after breaking. Results fit the test data well, which shows that the VOF method is suitable to numerical simulation of regular waves after breaking. Besides, the breaker coefficient B of regular waves in the bore model is a 相似文献
8.
A physical parameter, μb, which was used to meet the forcing of primary short waves to be off-resonant before wave breaking, has been considered as an applicable parameter in the infra-gravity wave generation. Since a series of modulating wave groups for different wave conditions are performed to proceed with the resonant mechanism of infra-gravity waves prior to wave breaking, the amplitude growth of incident bound long wave is assumed to be simply controlled by the normalized bed slope, βb. The results appear a large dependence of the growth rate, α, of incident bound long wave, separated by the three-array method, on the normalized bed slope, βb. High spatial resolution of wave records enables identification of the cross-correlation between squared short-wave envelopes and infra-gravity waves. The cross-shore structure of infra-gravity waves over beaches presents the mechanics of incident bound- and outgoing free long waves with the formation of free standing long waves in the nearshore region. The wave run-up and amplification of infra-gravity waves in the swash zone appear that the additional long waves generated by the breaking process would modify the cross-shore structure of free standing long waves. Finally, this paper would further discuss the contribution of long wave breaking and bottom friction to the energy dissipation of infra-gravity waves based on different slope conditions. 相似文献
9.
TAO Jianhua 《中国海洋工程》2001,(2):269-280
The "surface roller" to simulate wave energy dissipation of wave breaking is introduced into the random wave model based on approximate parabolic mild slope equation in this paper to simulate the random wave transportation including diffraction, refraction and breaking in nearshore areas. The roller breaking random wave higher-order approximate parabolic equation model has been verified by the existing experimental data for a plane slope beach and a circular shoal, and the numerical results of random wave breaking model agree with the experimental data very well. This model can be applied to calculate random wave propagation from deep to shallow water in large areas near the shore over natu ral topography. 相似文献
10.
Numerical study of wave and longshore current interaction 总被引：1，自引：0，他引：1
Wave and longshore current interaction was examined based on the numerical models.In these models,water waves in the presence of longshore currents were modeled by parabolic mild slope equation,and wave breaking induced longshore currents were modeled by shallow water equation.Water wave provided the radiation stress gradients to drive current.Wave and longshore current interactions were considered by cycling the wave and longshore current models to a steady state.The experiments for regular and irregular breaking wave induced longshore currents by Hamilton and Ebersole（2001） and Reniers and Battjes（1997） were simulated.The numerical results indicate that the present models are effective for simulating the interaction of wave and breaking wave induced longshore currents,and the numerically simulated longshore current at wave breaking point considering wave and longshore current interaction show some disagreement with those neglecting the wave-current interaction,and the breaking wave induced longshore current effect on wave transformation is not obvious. 相似文献
11.
On the parameterization of drag coefficient over sea surface 总被引：1，自引：0，他引：1
Six parameterization schemes of roughness or drag coefficient are evaluated on the basis of the data from six experiments. They present great consistency with measurement when friction velocity u*<0.5 m/s (approximately corresponding to 10 m wind speed U10 <12 m/s) and large deviation from measurement when u*≥0.5 m/s (approximately U10≥12 m/s). In order to improve the deviation, a new parameterization of drag coefficient is derived on the basis of the similarity theory, Charnock relationship and Toba 3/2 power law. Wave steepness and wind-sea Reynolds number are considered in the new parameterization. Then it is tested on the basis of the measurements and shows significant improvement when u*≥0.5 m/s. Its standard errors are much smaller than the ones of the other six parameterizations. However, the new parameterization still needs more tests especially for high winds. 相似文献
12.
内波破碎引起的能量耗散和混合是海洋内部的重要物理过程。通过在二维内波水槽进行实验室实验,分析内波与地形的作用,探究内孤立波与平顶海山地形作用时波要素、能量以及湍耗散率的时空变化。本实验利用重力塌陷法在两层流体中制造第一模态内孤立波,通过粒子图像测速技术(particle image velocimetry, PIV)获得内孤立波与地形作用时的流场结构,定量分析整个作用过程。结果表明,地形会改变波形甚至引起破碎,内波与地形作用时,振幅和能量密度会在内孤立波爬坡时迅速增大,在地形前缘产生强烈能量耗散。入射波的能量与塌陷高度呈二次函数关系,透射波能量随地形升高减小,反射波能量随地形升高增大。地形前缘局地湍耗散率极值时间序列在部分实验中呈双峰结构,对应内孤立波界面处剪切加强引起湍流耗散和波后缘翻转破碎。破碎引起的地形前缘区域平均湍耗散率量级在10~(-5)m~2/s~3,局地湍耗散率极值与入射波振幅呈指数关系,所有实验中局地湍耗散率的最大值接近10~(-3) m~2/s~3量级。 相似文献
13.
CO2 exchange at air-sea interface in the Huanghai Sea 总被引：3，自引：0，他引：3
INTRODUCTIONTheroleoftheoceaniscrucialintheoverallcycleofCOZ,withitsspecialpumpingmechanismssuchassolubilitypumpingattheair-seainterfacewithcarbonatechemistry,biologicalpumpinginsurfacewatersandalsointhewatercolumn,anddynamicpumpingassociatedwithoceancirculation(BroeckerandPeng,1982).Inordertounderstandthesevariouspumpingprocessesintheocean,muchresearchhasbeencarriedoutonaglobalscaleasapartofeffortstounderstandtheglobalgeochemicalcycleofCOZ.TheHuanghaiSea,atypicalmid-latitudeepicontine… 相似文献
14.
Zhuangcai Tian Lei Jia Naili Hu Susheng Wang Mingwei Zhang Guoqing Zhou 《海洋学报(英文版)》2023,42(2):142-149
Internal solitary wave(ISW) is often accompanied by huge energy transport, which will change the pore water pressure in the seabed. Based on the two-dimensional Biot consolidation theory, the excess pore water pressure in seabed was simulated, and the spatiotemporal distribution characteristics of excess pore water pressure was studied. As the parameters of both ISW and seabed can affect the excess pore water pressure, the distribution of pore water pressure showed both dissipation and phase lag... 相似文献
15.
中国近海生态动力学模型参数敏感性研究 总被引：3，自引：2，他引：1
In order to develop a coupled basin scale model of ocean circulation and biogeochemical cycling,we present a biogeochemical model including 12 components to study the ecosystem in the China coastal seas(CCS).The formulation of phytoplankton mortality and zooplankton growth are modified according to biological characteristics of CCS.The four sensitivity biological parameters,zooplankton assimilation efficiency rate(ZooAE_N),zooplankton basal metabolism rate(ZooBM),maximum specific growth rate of zooplankton(μ_(20)) and maximum chlorophyll to carbon ratio(Chl2C_m) are obtained in sensitivity experiments for the phytoplankton,and experiments about the parameter μ_(20'),half-saturation for phytoplankton NO_3 uptake(K_(NO_3)) and remineralization rate of small detritusN(SDeRRN) are conducted.The results demonstrate that the biogeochemical model is quite sensitive to the zooplankton grazing parameter when it ranges from 0.1 to 1.2 d~(-1).The K_(NO_3) and SDeRRN also play an important role in determining the nitrogen cycle within certain ranges.The sensitive interval of KNO_3 is from 0.1 to 1.5(mmol/m~3)~(-1),and interval of SEdRRN is from 0.01 and 0.1 d~(-1).The observational data from September 1998 to July 2000 obtained at SEATS station are used to validate the performance of biological model after parameters optimization.The results show that the modified model has a good capacity to reveal the biological process features,and the sensitivity analysis can save computational resources greatly during the model simulation. 相似文献
16.
基于物理模型试验,考虑畸形波参数、相对板宽、相对波高等影响因素,就畸形波对平顶双层水平板防波堤作用进行研究。首先对畸形波作用下双层水平板的波浪力分布特征进行了讨论,然后就最大波动压强、结构最大总垂向力与不规则波作用进行了对比分析。结果表明,畸形波作用下,双层水平板最大波动压力出现在前端迎浪区域附近,向尾端逐渐递减。双层水平板4个受力面的压力分布不同且有相位差,4个受力面的最大波动压力时间差约在0.1Tp~0.4Tp范围内变化。与不规则波作用比较,畸形波作用没有显著改变波压包络分布特征,但增大了波压包络强度值。试验范围内,就最大总力而言,两者最大总浮托力比值在1.06~2.45间变化;向下的最大总垂向力比值在1.22~2.07之间变化;就波动压力而言,其增大的幅度与畸形波参数α1相关性最强,随α1的增大而增大,在α1=2.04~3.1试验范围内,畸形波作用时的最大压强比不规则波作用时可约增大20%~80%。就最大波吸力而言,两者的比值与畸形波参数α4相关性最强,随α4的增大而减小。在α4=0.62~0.75试验范围内,最大波吸力强度的比值在1.61~0.87范围内变化。当α4≤0.72时,畸形波作用时的最大波吸力大于不规则波作用时的最大波吸力;当α4 > 0.72时则刚好相反。 相似文献
17.
南海北部陆架区内孤立波向岸传播过程研究 总被引：1，自引：0，他引：1
南海北部是全球海洋中内孤立波最强和最为活跃的海域。然而,内孤立波在传入陆架区后,其形态发生显著变化,其传播演变过程表现出高度的复杂性。本研究综合卫星图像和数值模式手段研究了内孤立波在向岸传播过程中的空间变化特征。可见光卫星图像研究结果显示,南海北部陆架区存在三种形态的内孤立波,分别为第一模态下凹型内孤立波、第一模态上凸型内孤立波和第二模态内孤立波。受水深和层结变化的控制,它们的分布区域显著不同。基于MITgcm的数值模拟研究表明,上凸型内孤立波由第一模态下凹内孤立波经过极性转换过程发展而来,而第二模态内孤立波由第一模态下凹内孤立波与急剧变浅地形相互作用而产生。 相似文献
18.
Chen-Yuan CHEN I-Fan TSENG Hsien-Chueh Peter YANG Cheng-Wu CHEN Tsung-Hao CHEN 《中国海洋工程》2006,20(4):585-594
1 .IntroductionWhile surface solitary waves arefoundin many physical phenomena (Chouand Shih,1996 ;Chouand Quyang,1999 ;Chouet al .,2003 ; Chenet al .,2004 ; Wang,2004 ;Tsenget al .,2005) ,internal solitary waves (ISWs) have been observed since the beginning of the 20th century.In fact ,some internal waves have alarge enoughamplitudeto cause consequence onthe surface .Hence obser-vation of the oceansurface may helpto detect the activities of internal waves . We require observationsthrough… 相似文献