渤海南部海域年极值波浪和设计波浪的特征研究   总被引：1，自引：0，他引：1  

滕学春  吴秀杰 《海洋科学进展》1994,(3)

本文用统计计算和后报方法，获得了本海域不同海区多年年极值波高（Ｈ１／１０）资料。用Ｐ－Ⅲ型和短期测波资料频率分析方法，估算了各海区的设计波高，并依据文献［３］计算出对应的平均周期。用Ｋｏｌｍｏｇｏｒｏｆｆ适合度方法检验所得的结果表明，依Ｐ－Ⅲ型方法拟配的理论频率曲线与经验点十分吻合，从而确定了本海域不同海区最佳的设计波浪。分析本海域年极值波浪的基本特征表明，本海域除了渤海湾北部海区以外，主浪向一般为ＮＮＥ向，渤海海峡区的年极值波高和设计波高均为最大，而向莱州湾及渤海湾沿岸海区逐渐减小；在沿岸海区，由龙口至黄河口一带的极值波高较大。  相似文献   

规则波和不规则波作用下消波建筑物前的波高分析   总被引：1，自引：0，他引：1  

李荣庆  谢世楞 《海洋工程》1994,(1)

消波建筑物在国内外已得到广泛应用。本文采用近似方法分析了明基床上直立式消波建筑物前的波高及消波室内的波高，从而确定建筑物的消波效果。并在规则波的基础上将成果推广至不规则波作用下的情况。  相似文献   

风浪频谱中的特征量   总被引：4，自引：3，他引：4       下载免费PDF全文

侯一筠  王涛 《海洋与湖沼》1993,24(2):126-131

在三参量风浪频谱的基础上对谱参量进行深入地研究,给出了谱参量与风场要素、波场要素的关系,提供了依据风场要素、波场要素及实测波浪资料计算谱参量的方法。从而可以依据上述因素直接计算出三参量风浪频谱。此外还根据谱宽度的变化,描述了风浪频谱的成长方式,解释了传统的波陡、波龄关系中经验常数的不同选取所代表的物理背景。  相似文献   

Effect of wave-directionality on second-order loads induced by the set-down     

B. Molin  V. Fauveau 《Applied Ocean Research》1984,6(2):66-72

At first-order of approximation a sea-state may be considered as an infinite sum of Airy components with angular frequencies ω_i and wave-number vectors k_i. A second-order analysis shows the co-existence of long waves appearing at the difference frequencies ω_i—ω_j with wave-number vectors k_i—k_j. In shallow water they become appreciable in amplitudes and may induce slow-drift motion of moored structures.For small values of ω_i—ω_j,k_i—k_j may take all kinds of directions for an angular-spread wave system. Then it may be questioned how the in-line and transverse second-order accelerations compare to those obtained for a mono-directional wave-system.This analysis is carried out here by relating the spectra of the second-order horizontal accelerations to the directional wave-spectrum. Numerical applications are first performed for deep water. They show that at low frequencies, even for very narrowly spread wave systems, the transverse component is larger than the in-line component. In shallow water both components are dratically reduced as compared to the mono-directional case. As a consequence one may question the validity of model-testings or numerical models which take no account of the directionality of the wave-system.  相似文献   

Scattering of Semidiurnal Internal Kelvin Wave at Step Bottom Topography     

Yuji?KawamuraEmail author  Yujiro?Kitade  Masaji?Matsuyama 《Journal of Oceanography》2005,61(1):59-68

A three-dimensional, multi-level model was used to study the energy dissipation of semidiurnal internal Kelvin waves due to their interaction with bottom topography. A simplified topography consisting of a channel with an additional shallow bay was used to clarify the wave’s scattering process. When the first mode semidiurnal internal wave given at an open boundary arrives at the bay mouth, higher-mode internal waves are generated at a step bottom of the bay mouth. As a result, the energy of the first mode internal Kelvin wave is effectively decayed. The decay rate of the internal Kelvin wave depends on both the width and length of the additional bay. The maximum decay rate was found when a resonance condition occurs the bay, that is, the bay length is equal to a quarter of wave length of the first mode internal wave on the shallow region. The decay rate in the wide bay cases is higher than that in a narrow case, due to a contribution from the scattering due to the Poincare wave that emanates from the corners of the bay head. The decay rate with the additional bay is 1.1–1.8 times that of the case without the additional bay. The decay rate due to the scattering process is found to be of the same order as that of the internal and bottom friction.  相似文献   

On the recovery of surface wave by pressure transfer function     

Cheng-Han Tsai  Min-Chih Huang  Fu-Ji Young  Yin-Chern Lin  Hsien-Wen Li 《Ocean Engineering》2005,32(10):4936-1259

Except the commonly selected pressure transfer function derived from the linear wave theory, a previous study on the pressure transfer function for recovering surface wave from underwater pressure transducer suggested that the pressure transfer function is a function of frequency parameter only. With careful analysis, this study showed that the pressure transfer function should include a transducer submergence parameter as that given by the linear theory. It was found that the previously suggested empirical formula should be restricted to measurements with the pressure transducer close to the surface; otherwise overestimation of wave height would result. Field measurements were carried out with an acoustic wave gauge and a synchronized pressure transducer located at various depths with submergence parameter close to 1 (near the sea floor). It was shown that the previous one-parameter empirical formula might overestimate the significant wave height by more than 30%. This study found that with deep-water wave bursts excluded, the transfer function based on the linear wave theory provided a fairly good estimation on the significant wave heights, with an average deviation of 3.6%.  相似文献   

钦州湾潮流特征分析   总被引：9，自引：0，他引：9  

邱绍芳  侍茂崇  陈波 《海洋通报》2003,22(3):9-14

根据1994年5月和11—12月两个航次的调查及近年有关海湾的海流观测资料，分析了钦州湾的潮流特征，观测资料来自分布于该海湾东中西三个航道及相关区域的8个测站。钦州湾涨落潮流特征：落潮流速大于涨潮流速：东部最大涨落潮流速小于西部：夏季落潮流总是大于冬季：龙门水道附近的流速最大，而其余区域的流速相对较小。外湾(钦州湾)余流，是气旋式环流：水体东进而西出。从湾内来的泥沙和污染物质，主要从西部进入外海；中、东槽是主要“进水”通道，外海低泥沙含量、少污染物质的清洁水从这里潮流而上。因此，与西部相比，东部盐度高，水质清洁，底质重金属含量少。  相似文献   

Fuzzy Fatigue Reliability Analysis of Offshore Platforms in Ice-Infested Waters   总被引：3，自引：3，他引：3  

方华灿  段梦兰  贾星兰  谢彬 《中国海洋工程》2003,17(3)

1 .IntroductionTheBohaiGulfisinfestedbyiceinthewholewinter,andoffshorestructuresthereexperiencenotonlywind ,waves ,currentsandearthquake ,butalsoiceloadswhicharecomplicatedbecauseofthedynamicinteractionbetweenicesheetsandstructures.Duanetal.( 2 0 0 0 )hadacomprehensivere viewofthelatestadvancesonice inducedvibration ,fatigueandfractureofoffshorestructures ,payingmuchattentiontothedifferencesinicebreakingmodeanddynamicsofstructuresindifferentice in festedwaters .Theypresentedcriticallythelates…  相似文献   

Wave-Current Forces on Vertical Cylinders in Side-by-Side Arrangement for Irregular Waves Combined With Opposing Current     

Li Yucheng Wang Fenglong Professor  Dalian University of Technology  Dalian Senior Engineer  Dalian University of Technology  Dalian 《中国海洋工程》1993,(1)

- The wave-current forces on vertical piles in side-by-side arrangement induced by irregular waves with opposing current are investigated experimentally in this paper. The characteristics in both time and frequency domain of in-line, lift and resultant forces are analyzed. The grouping effect coefficients of inline, lift and resultant forces on piles related to KC number and relative spacing parameters are given. These results are compared with those in the case of irregular waves combined with following currents. It is found that the results in these two cases are quite different. The range of KC number tested is 10- 60, the range of Reynolds number is (0.55-3.43) ×104.  相似文献   

Test Study on Current Force on Mooring Ships     

Zhang Furan  Zhao Jun Zhang Xueqin Assistant Researcher  Tianjin Research Institute of Water Transport Engineering  Tianjin Assistant Engineer  Tianjin Research Institute of Water Transport Engineering  Tianjin 《中国海洋工程》1993,(2)

In respect of an offshore berthing pillar, the test study result of current force acting on mooring ships is described in this paper. Empirical and semi-empirical relationships of current force coefficient are given according to the angle between the flow direction and the ship's longitudinal axis, which are coincident with the result of theoretical analysis.  相似文献