水槽造流系统水力计算与泵机选择

提供一种完整的用于试验水槽造流系统的水力计算和泵机选择方法，可用于其他类似工程设计。     

桶基平台压沉贯过程汲水泵机的初步水力分析

对桶形基础平台负压沉贯过程中汲水泵机进行了初步水力分析,讨论了不同水深、不同泵机安装高度情况下,桶腔和泵机进口之间的压头关系。这些结果可作为实际工作中选择泵机类型及其安装高度的参考。     

深水造流系统数值模拟与实测验证

通过求解N-S方程和SST k-ω湍流模型对深水造流系统进行了时域模拟。为了提高数值计算的精度,准确扑捉流场的细节,采用多块结构化网格技术生成流体域网格。分析深水试验区域的流场分布规律,给出水流速度沿横向方向的分布情况,计算流场稳定所需要的时间。为了验证数值计算的准确性,对海洋深水造流系统进行实测试验。计算值与试验值吻合较好,证明该方法的可行性。数值模拟的结果对合理选取试验区域,了解造流系统的相关特性,有效控制水池内水流速度,提高海洋深水试验的精确度具有相当重要的作用。     

小型室内水槽造波造风系统设计

小型室内风浪水槽是海气界面多种微尺度过程实验研究的基础设施.造风造波系统是风浪水槽的核心部分.针对多种微尺度过程模拟的需要,设计了造风造波系统的硬件结构与控制软件.利用该系统,开展了多种造波、造风实验.通过对实验数据的分析,证明该设计满足各项预定指标,可以有效模拟多种海气界面风浪环境.     

台阶式变深水槽造波的解析研究台阶式变深水槽造波的解析研究

利用特征函数展开法对台阶式变深水槽中推板式造波机造波问题进行了研究,建立了相应速度势和波面的解析表达式。与高阶边界元方法(HOBEM)数值结果进行了对比,验证了本解析解的正确性。通过数值试验,研究了台阶对入射波的影响,同时分析了造波板所在位置（上部台阶）水深、水槽工作区（下部台阶）水深、造波板运动周期和造波板水平位置等因素对生成波浪高度的影响。由此选择合适的造波板所在位置及水深来得到所需要的波浪高度,进而根据需要生成波浪的周期和波幅 来反演造波板的运动。     

台阶式变深水槽造波的解析研究

利用特征函数展开法对台阶式变深水槽中推板式造波机造波问题进行了研究,建立了相应速度势和波面的解析表达式。与高阶边界元方法(HOBEM)数值结果进行了对比,验证了本解析解的正确性。通过数值试验,研究了台阶对入射波的影响,同时分析了造波板所在位置(上部台阶)水深、水槽工作区(下部台阶)水深、造波板运动周期和造波板水平位置等因素对生成波浪高度的影响。由此选择合适的造波板所在位置及水深来得到所需要的波浪高度,进而根据需要生成波浪的周期和波幅来反演造波板的运动。     

小型内波实验水槽及其供水、造波与量测系统

本文介绍了作者们设计并制造的小型内波实验水槽系统,它包括水槽、双缸法供水系统、造波与消波装置以及量测与显示手段。实验表明,此系统性能良好,可进行内波科研与教学实验。     

双边多单元造波机造波性能分析

由若干独立摇板组成的多单元造波机是实验室研究波浪及其与海洋工程结构物相互作用的重要设备。由于单元摇板宽度和波浪周期对斜向波浪模拟方向角的限制、斜向波浪模拟引起的杂波和三维短峰波浪模拟的有效实验区范围等,是影响多单元造波机波浪模拟质量的关键问题。通过对海洋深水池双边多单元造波机性能的分析,获得了波向角与规则波浪周期的关系,避免杂波产生的波浪周期范围和三维短峰波浪有效实验区的范围。分析结果对于海洋深水池高质量模拟波浪并为海洋工程结构物模型试验提供良好的波浪环境条件具有重要意义。     

单纯流作用下的系缆式剖面测量模型静水力分析与计算

文中介绍了系缆式剖面测量模型在波浪水槽实验室的试验情况,对试验中匹配的系泊模型系统进行了静力分析。通过对模型系统的单纯流作用下的静力计算结果与试验数据的对比,针对理论计算的有效性进行了讨论。     

基于代理模型的喷水推进泵水力特性分析及优化

采用代理模型的整体敏感度分析方法对模型泵的结构参数(叶轮叶片进口安放角和出口安放角) 进行优化设计。研究结果表明：叶轮出口安放角对喷水推进泵效率和轴功率影响较大,整体敏感度分别约为 95%和 68%;进口安放角的影响相对较小,整体敏感度分别为 5%和 32%。优化后的叶轮进口安放角和出口安放角分别为 0.69°和 3.92°,满足 Pareto 最优解,喷水推进泵效率提高了 1.7%,功率密度提高了 6%。     

一种浅水型海流定点观测系统布放方法

介绍了采用座底式轻型仪器架进行30 m以内浅水深海流观测的两种系统布放方法:先锚后仪器架法和先仪器架后锚法。其中,详细介绍了先锚后仪器架法的布放过程,对先仪器架后锚法作了简要介绍。     

渤海及黄海北部的风海流数值计算及余流计算

依据黄渤海实测风的资料对渤海及北黄海进行了月平均风海流数值计算。计算表明 ,1月份在西北风的作用下 ,在渤海出现 1个逆时针旋转的环流 ,在辽东湾北部及黄海北部出现 1个顺时针旋转的环流 ,渤海海峡的海流北进南出。 7月份在南风和东南风的作用下 ,风海流的变化形式与 1月份大致相反 ,海峡处呈南进北出的形式。对渤海中部某点 1年的潮流资料通过低通滤波的方法计算逐时的余流值 ,得到该点 1年内表层最大的实测余流为 31.9cm/ s,全年 90 %多的时间内表层余流小于 10 cm/ s。对辽东湾北部某点和渤海湾西南部某点数月潮流资料也进行了低通滤波 ,并将得到的逐时余流与同步风作了比较。依据该 2点风和余流的关系以及黄海北部 6个点风和余流的关系验证了风海流数值计算的结果 ,表明在这些点上实测与计算结果拟合良好     

桶基平台负压沉贯过程汲水泵机的初步水力分析

对桶形基础平台负压沉贯过程中汲水泵机进行了初步水力分析,讨论了不同水深、不同泵机安装高度情况下,桶腔和泵机进口之间的压头关系.这些结果可作为实际工作中选择泵机类型及其安装高度的参考.     

冬季黄海暖流的诊断计算

采用ECOMSED三维水动力模式，诊断计算了冬季渤海、黄海和东海的近海环流状况，重点分析了黄海暖流的演变过程及其垂直结构，并探讨了黄海暖流的形成机理。结果表明，黄海暖流于12月初步形成，次年2月发展最强盛，3月开始衰退。黄海暖流在表层和次表层（0-30m）并不是一支持续稳定的流，其持续稳定性仅在近底层得到很好的体现。对黄海暖流形成机理的分析表明，压强梯度力、垂向摩擦力和柯氏力占主要地位。在表层及次表层，主要表现为风的正压作用，而在近底层，则由海平面起伏造成的正压梯度力和密度场引起的斜压梯度力形成的总压强梯度力与柯氏力基本平衡，因而黄海暖流可基本认为是准地转流。     

Laboratory Study on the Hydraulic Conductivity and Pore Pressure of Sand-Silt Mixtures

The hydraulic conductivity plays a major role on the excess pore pressure generation during monotonic and cyclic loading of granular soils with fines. This paper aims to determine how much the hydraulic conductivity and pore pressure response of the sand-silt mixtures are affected by the percentage of fines and void ratio of the soil. The results of flexible wall permeameter and undrained monotonic triaxial tests performed on samples reconstituted from Chlef River sand with 0, 10, 20, 30, 40, and 50% nonplastic silt at an effective confining stress of 100 kPa and two relative densities (D_r = 20, and 91%) are presented and discussed. It was found that the pore pressure increases linearly with the increase of the fines content and logarithmically with the increase of the intergranular void ratio. The results obtained from this study reveal that the saturated hydraulic conductivity (k) of the sand mixed with 50% low plastic fines can be, on average, four orders of magnitude smaller than that of the clean sand. The results show also that the hydraulic conductivity decreases hyperbolically with the increase of the fines content and the intergranular void ratio.     

Computation of Wave, Tide and Wind Current for the South China Sea Under Tropical Cyclones

Based on the third-generation oceanic wave prediction model (WAVEWATCH Ⅲ) ,the third-generation nearshore wave calculation model (SWAN) and the mathematical tide, tidal current and cyclone current model, which have been improved, interconnected and expanded, a coupled model of offshore wave, tide and sea current under tropical cyclone surges in the South China Sea has been established. The coupled model is driven by the tropical cyclone field containing the background wind field. In order to test the hindcasting effect of the mathematical model, a comparison has been made between the calculated results and the observational results of waves of 15 cyclone cases, water levels and current velocities of the of 7 cyclones. The results of verification indicate that the calculated and observed results are basically identical.     

Mechanics of a Grip System of Three-Key-Board Hydraulic Tongs Developed for Offshore Oil Pipe Lines

-This paper carries out the analysis of mechanics of a grip system of three-key-board hydraulictongs developed for offshore oil pipe lines which has been successfully used in oil fields in China.The mainimprovement of this system is that a lever frame structure is used in the structural design,which reducesgreatly the stresses of the major components of the oil pipe tongs.Theoretical analysis and numerical calcu-lation based on thirteen basic equations developed show that the teeth board of the tongs is not easy to slipas frequently happens to other systems and is of higher reliability.     

埕岛油田潮流、风海流预报系统的研制与应用

在埕岛油田潮流、风海流预报系统中应用了整体潮流预报法,结合对本海域潮流实测资料,研究编制成操作简便、功能强大的潮流预报应用软件,实现了对埕岛海域潮流和风海流的即时预报,用于指导油田生产管理,并取得了较好的效果。     

Current Measurements of the Japan Sea Proper Water and the Intermediate Water by ALACE Floats

The subsurface current of the Japan Sea was observed by two Autonomous Lagrangian Circulation Explorer (ALACE) floats. One float, having a 20-day cycle, was deployed on 29 July 1995 in the eastern Japan Basin and drifted in the northeastern part of the basin until 15 September 2000. The other float, with a 10-day cycle, was deployed on 4 August 1995 in the western Japan Basin and drifted in the western Japan Basin, in the Yamato Basin and around the Yamato Rise until it reached its life limit in mid-May 2000. An anticlockwise circulation in the eastern Japan Basin was observed and it was assumed to be in the upper portion of the Japan Sea Proper Water (UJSPW) or in the intermediate water. The spatial scale of the circulation increased as the depth decreased. A clockwise circulation was observed around the Yamato Rise in the UJSPW. Smaller clockwise and anticlockwise rotations were observed in the western Japan Sea, where a seasonal variation was seen in drift speed with different phase by depth. The correlation coefficient between drift speeds of two floats indicated little coherence among the subsurface circulation between the east and the west of the Japan Basin, or between the north and the south of the subpolar front. This revised version was published online in August 2006 with corrections to the Cover Date.