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1.
海浪对海洋上层的动量与混合作用分析   总被引:2,自引:0,他引:2  
分析了波浪影响海洋环流的3种机制,给出了波浪对海流的雷诺应力表示、搅拌混合系数表示以及对温盐扩散的搅拌混合系数表示;计算了东中国海区域的波浪动量作用、搅拌混合系数空间分布和时间演化,进而定量分析了波浪对表层海流的动量输送及对海洋上混合层与跃层形成的作用。  相似文献   

2.
上层海洋中浪致混合研究评述——研究进展及存在问题   总被引:1,自引:0,他引:1  
本文较系统地分析和总结了海浪在上层海洋中的混合作用研究的国内外现状,分别探讨了海浪破碎、波生运动以及波-湍相互作用导致的混合作用,指出了现有研究存在的问题。对今后研究做一展望,并指出实验室热分层水槽中的系统实验研究的必要性。  相似文献   

3.
Threshold of Sediment Movement in Different Wave Boundary Layers   总被引:3,自引:2,他引:3  
A review of former studies on the onset of sediment movement under wave action reveals that the Shields criterion obtained in unidirectional steady flow can also be applicable to oscillatory unsteady flow when the boundary layer is the same. In this paper, through comparison of different boundary layers in wave and steady flow conditions, a new criterion is presented which can be used to predict the threshold of sediment movement under wave action. The criterion curve shows good agreement with the experimental data.  相似文献   

4.
理论导出的非匀质波场波向对变风向响应的模式表明,单点波浪观测资料不足以提供非匀质情况下波向对变风向响应的信息。基于理论模式,提出了采用仪器阵列进行波浪观测研究波向响应的观测设计方案。  相似文献   

5.
刘诚  梁燕  彭石  侯堋 《海洋学报》2017,39(1):1-10
本文建立曲线坐标系下的双曲型缓坡方程波浪模型和考虑波浪辐射应力影响的深度平均2D潮流数学模型,首次研究了磨刀门河口2011年地形条件下的枯季波生流场。受波浪作用影响,落潮阶段,波浪作用方向与流向相反,在波浪顶托效应下拦门沙沙脊及外坡处流速普遍减小,形成两个主要回流区,口门外东西两侧浅滩处流速也减小,东西两汊及横洲深槽流速增大;涨潮阶段,波浪作用方向与流向相同,拦门沙沙脊及外坡处流速增大,沙脊处出现冲越流,口门两侧浅滩处流速增大,横洲深槽流速减小。  相似文献   

6.
The Mechanism Analysis of Seafloor Silt Liquefaction Under Wave Loading   总被引:5,自引:0,他引:5  
The sediment in Chengbei area of the Huanghe (Yellow River) subaqueous delta is the object of a reseach project in this article. The accumulating and dissipating effects following the change of time are considered first in the study area and the distributing curves of excess pore water pressure along with time and depth in the soil stratum are gained; the possibility of silt liquefaction is evaluated using the computing values and the affecting depth of liquefaction is given. This paper quantitatively analyzes the dynamic response of seafloor soil under the cyclic loading of waves and makes an inquiry into the instable mechanism of soil.  相似文献   

7.
本文基于波能平衡方程,通过考虑波的传播项,即,研究波场非匀质性对波向对变风向的响应的影响。导出的结果表明,响应的时间尺度可由3部分表示:1.匀质情形响应的贡献;2.波能分布非匀质性的影响;3.平均波向分布非匀质性的影响。在理论上,它暗示波场的非匀质性在波向响应中起着实质性的作用;在实际情况下,对匀质和平稳风场,波场的非匀质性总是使响应时间尺度减少这一事实进行了讨论。  相似文献   

8.
波浪破碎诱导生成的海盐粒子是海洋向大气输运无机盐的主要机制,海气界面的无机盐通量对于全球气候变化有重要影响。本文开展了实验室实验模拟海盐粒子生成实验,定量考察了温度和盐度对海盐粒子中离子质量分布的影响,揭示了初生海盐粒子中各离子的富集和亏损现象与温度和盐度的关系。基于实验室观测分析结果和推测假定,提出了1个既包含海面风速、又反映海表温度和海表盐度影响的海-气无机盐通量参数化方案。将此参数化方案应用于估计海盐粒子向大气输运的各种无机盐离子质量通量,并与传统方法估算结果进行了比对分析。  相似文献   

9.
In consideration of the effect of the internal flowing fluid and the external marine environmental condition on the vortex-induced vibration (VIV) of top tensioned riser (Till), the differential equation is derived based on work-energy principles and the riser near wake dynamics is modeled by Facchinetti' s wake oscillator model. Then Galerkin' s finite element approximation is implemented to derive the nonlinear matrix equation of the coupled equations and file corresponding numerical programs are compiled which solve the coupled equations directly in the time domain. The comparison of the predicted results with the recent experimental results and the prediction of SHEAR7 is performed. The results show the validity of the proposed method on the prediction of VIV of deep water risers. The effect of internal flow on the dynamic characteristics and dynmnic response of the riser is analyzed and several valuable conelusions are drawn.  相似文献   

10.
This paper reveals that the long-period statistic distribution of the characteristic heights of deep-water waves assumes the lognormal distribution. Thereafter, the largest wave-height which may occur in the service life of coastal structures is derived in this paper.  相似文献   

11.
鉴于海洋边界层内风、浪相互作用在海洋、大气研究中的重要意义,本文较详细地回顾、总结了国内外有关海洋边界层风、浪相互作用的研究进展:由最初的关于风应力和空气动力粗糙长度的统计研究发展到后来的利用模式探讨海洋边界层的结构和风、浪耦合机制。最后简单讨论了风、浪耦合研究中存在亟待解决的问题以及未来的研究前景。  相似文献   

12.
More and more researches show that neither the critical downward acceleration nor the critical slope of water waves is a universal constant. On the contrary, they vary with particular wave conditions. This fact moders the models either for the probability of wave breaking B or for the whitecap coverage W based on these criteria difficult to apply. In this paper and the one which follows we seek to develop models for the prediction of both B and W based on the kinematical criterion. First, several joint probabihstic distribution functions (PDFs) of wave characteristics are derived, based on which the breaking properties B and W are estimated. The estimation is made on the assumption that a wave breaks ff the horizontal velocity of water particles at its crest exceeds the local wave celerity, and whitecapping occurs in regions of fluid where water particles travel faster than the waves. The consequent B and W depend on wave spectral moments of orders 0 to 4.Then the JONSWAP spectrum is used to represent the fetch-limited sea waves in deep water, so as to relate the probahility of wave breaking and the whitecap coverage with wind parameters. To this end, the time-averaging technique proposed by Glazman (1986) is applied to the estimation of the spectral moments involved, and furthermore, the theoretical models are compared with available observations collected from published literature. From the comparison, the averaging time scale is determined. The final models show that the probability of wave breaking as well as the whitecap coverage depends on the dimensionless fetch. The agreement between these models and the database is reasonable.  相似文献   

13.
Using the axial symmetry results of marker and cell (MAC) method as initial value in this paper, two numerical calculating methods are presented for the late wavemaking response induced by explosion in harbour. One of the methods is the superposition method of the vibration mode based on fluid slosh in container. Another one is the joining method of the MAC results with the shallow wave theory calculation in time domain. As a practical example, it is conducted to the numerical calculation about 1000 ton TNT equivalent explosion within touch of water surface. The results show that it can be rationally described with the methods to the wavemaking progress and character. The numerical results are identical with the observed scene on the spot experiment. The methods are simple and applicable in the engineering design.  相似文献   

14.
范有明 《海洋技术学报》2007,26(3):24-26,41
"波浪与海流测量仪器测试装置"依靠机械传动机构带动传感器作相对运动,模拟"波浪"和"海流"测量状态。测试装置为实现实验室内进行声学测波仪和声学矢量海流计的调机、考机、检测增添了有效可靠的技术手段。  相似文献   

15.
本文基于海上与其附近沿岸台站短期观测资料的分析,建立了两种关系:一种是海上的风速与浪之间的关系;另一种是海上与岸站两地风速之间的关系.通过这些关系,用岸站观测的风速资料可以得到海上的年极值波浪.采用 P—Ⅲ型、Gumbel 和 weibull 方法分别估算海上的设计波浪,结果彼此之间有较大的差异。选用柯尔莫哥洛夫(Kolmogoroff)适合度方法检验表明,估算设计波浪的波高用 P—Ⅲ型方法最好,而估算设计波浪的周期用 Weibull 方法最好。  相似文献   

16.
Standing waves are formed due to the reflection when waves meet vertical wall,thereforestrong structures are needed to keep the wall stability under the serious wave attack.For the improvementof the working condition and increase of the stability of the wall,the lower reflecting breakwaters have at-tracted close attention Reports mostly from Japanese researchers are often concerned with the wall ofcaisson equipped with open windows.In this paper a kind of hollow-pipe perforated breakwater is exam-ined which waves may partially perforate into the harbour basin.The wave in front of the wall can onlyform partial standing wave and wave force is reduced obviously.And the theoretical calculation of waveforce and analysis of wave force spectrum are all derived.Comparison between the results from theoreticalcalculation and hydraulic modeling shows reasonable agreement.  相似文献   

17.
回顾了我国波浪测量技术特别是近海波浪浮标技术的发展历程,提出了今后发展的若干建议。  相似文献   

18.
通过分析实验室风浪观测结果研究非线性效应对波面极大值和极小值分布的影响。波面极大值和极小值累积概率的差异表明 ,与线性理论相比 ,波面极小值在平均波面以下的位置偏高。对实验结果的进一步分析表明 ,非线性效应使波面极大值在平均波面以上总概率高于线性理论结果 ,而概率密度峰值处波面极大值高度略低于线性理论结果。波面极小值在平均波面以上各位置出现的概率均高于线性理论结果 ,在平均波面以下的较低位置 ,波面极小值出现概率明显低于线性理论结果。  相似文献   

19.
Understanding of sea bottom boundary layer characteristics, especially bottom shear stress acting on the sea bed, is an important step needed in sediment transport modeling for practical application purposes. In the present study, a new generation system for bottom boundary layer under solitary wave is proposed. Applicability of this system is examined by comparing measured and numerical solution velocities. Moreover, transitional behavior from laminar to turbulence was investigated. It is concluded that the critical Reynolds number in the experiments shows good agreement with DNS result of Vittori and Blondeaux (2008) and laboratory data of Sumer et al. (2010), indicating validity of the generation system. Since the present generation system enables continuous measurement to obtain ensemble averaged quantities, it can be effectively utilized for future experimental studies on solitary wave boundary layers, including sediment transport experiments with movable bed.  相似文献   

20.
基于普林斯顿(POM)模式,采用不同的垂直混合方案并考虑太阳短波辐射的作用,对渤海、黄海夏季垂直热结构进行了数值试验。试验结果表明,夏季波浪混合控制着渤海、黄海上混合层的形成,加入波浪混合能明显改善陆架浅海的夏季温度垂直结构。太阳短波辐射对渤海、黄海夏季上层垂直热结构有一定的作用,研究夏季海洋上层垂直热结构应该包括太阳短波辐射的影响,特别是对于水深相对较深的黄海。  相似文献   

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