塑料薄膜采水器

塑料薄膜水袋式采水器,不同于国内外现有的采水器,与南生式、有机玻璃及硬塑料简式和CIT式相比,它具有许多优点。这种采水器是由主架、聚乙烯薄膜水袋和释放器三部分组成。其特点如下: 1.每架采水器配有6只聚乙烯薄膜水袋,每只水袋均可自由装卸,能装水样4000ml,每架采水器总容量为24000ml。一次采水完全可满足无机、有机和放射化学分析用量。也可根据需要调节采水量4000ml至24000ml。     

电控多瓶采水器系统的优化设计

采水器是进行海水现场取样必不可少的仪器,电控多瓶采水器可以根据用户需要在预先设定的深度自动执行采水,具有智能化、灵活性和高可靠性的特点。该采水器控制系统采用单片机最小系统结构,外设电路简单而新颖。采用VB6.0编写人机交互界面,向控制系统发送指令和发送预设深度数值等。文中论述了电控多瓶采水器的系统组成、硬件电路优化设计、下位机及上位机软件工作流程,并介绍了采水器的测试方法和海上现场试验情况。     

XCP投弃式海洋探头阻力系数数值计算及试验研究

以XCP探头为模型,采用有限体积法结合κ-ε两方程湍流模型,对XCP探头阻力系数进行了数值计算,研究了XCP探头的阻力特性。获得了不同雷诺数下阻力系数的变化趋势和水下稳定运动时的极限速度。结果表明阻力系数随着雷诺数的增加而减小,其数值计算结果与海上实测数据基本吻合,验证了该数值计算方法的正确性,可为XCP探头结构设计提供参考。     

中底层海水石油类样品原位采水器设计

设计了一种用于采集中底层水样的海水石油类样品原位采水器。适用于分析水样中油类、生物类等指标。其主要特点是可以采集所需深度的水样,保持所采集水样的原位特征。与常见的采水器相比,该采水器采用"闭-开-闭"的采样瓶启闭模式,即把经过清洗处理的采样瓶装到采水器上,瓶口保持密封状态,下放到设定深度后,发出指令打开采样瓶瓶口,开始采水,采样瓶装满水样后,关闭采样瓶瓶口。闭-开-闭模式,保证了样品瓶采样前后始终处于密封状态,避免在采水器下放和提升过程中,采样瓶和采集的水样可能受到其他深度水体的污染和干扰。     

多瓶自动采水器首次进行海上试验

海洋技术研究所研制的多瓶自动采水器,今年六月二十日至七月六日参加了“向阳红16号”远洋考查,在太平洋上进行了首次深海采水试验,获得了较好结果。多瓶自动采水器其显著的特点就是能自动采取选定深度层次的水样。它是通过深度传感器测深,给出深度信号,用该信号控制采水器的释放机构,使采水瓶在选定的深度上自动进行采水。     

无人船FLUENT阻力模拟与试验验证

无人船作为一种新型的海上观测平台,其航行阻力性能研究非常重要。针对无人船复杂的船体结构,提出一种基于FLUENT软件的无人船阻力数值模拟方法。使用标准k-ε湍流模型和VOF方法,分别对无人船浮体及其附属物进行周围粘性流场的数值模拟。在不同傅汝德数条件下,计算得到双体船浮体的粘性阻力系数,并与经验公式计算结果相比较,结果一致性较好。进一步考虑无人船的附属物阻力,计算了无人船总阻力,经与湖试试验值比较,吻合较好。研究结果证明了该方法用于无人船阻力计算的适用性。另外,结合仿真数据,还对无人船阻力主要来源作了简要分析,可为无人船结构优化设计提供参考。     

一种无缆自动返回式采水器的机械设计

设计一种垂直剖面采水的自动返回式采水器,其机械机构由配重体的悬挂或释放装置及采水瓶关闭采水机构组成。配重体的悬挂或释放未采用螺纹密封和螺纹承重,动作由密封仓内电机的驱动转动和壳体端盖上的挂钩脱钩实现。采水瓶的关闭不涉及步进电机的转动,由电磁阀的通电实现。实践表明,采水器的机械设计结构简单有效,保证密封,操作方便。     

大容量海水采水器的研制

介绍一种实用新型的采水器，该采水器具有全新的开闭装置及密封结构．文章对采水器的构造、工作原理及特点进行了有益的探讨。     

软土地基中插入式大直径薄壁圆筒结构的一种简化数值计算方法

简述了对插入式大直径薄壁圆筒进行数值分析采用的力学机制，用弹簧元模拟薄壁圆筒与地基土体接触面间的连接所形成一种简化的数值计算模型，运用大型通用有限元软件ANSYS进行二次开发后对其进行数值计算与分析，比较了对筒内外淤泥粘土采用不同加固处理方法以及考虑相邻圆筒间采用不同边界约束条件时，对圆筒的应力和稳定性的影响。通过实例计算，验证了该数值模型的有效性与可行性，并得出一些有益结论。     

NMOHEMS探头外形对其下沉运动的影响分析

NMOHEMS 探头是一种由无人机运载的小型投掷式探头,采用混合网格技术结合湍流模型,建立了探头下沉运动的数值计算方法,分析了导流腔、收缩段及尾翼对探头下沉运动的影响;通过6种外形探头在不同雷诺数下的阻力系数和相同质量下的极限速度对比,发现探头外形对其下沉运动数值计算的结果影响较大;其中导流腔和收缩段均具有明显的减阻作用,且收缩段的影响更大,而尾翼具有一定的增阻作用;lgRe 在2.3~3.8时,6种外形探头的阻力系数差别较大,随着雷诺数的增加,阻力系数均迅速减小;lgRe 在3.8~5.1时,6者的阻力系数比较接近,虽仍然保持减小趋势,但变化趋于缓慢.NMOHEMS 探头的体型较小,下沉速度较慢,对其下沉运动进行数值计算时,必须考虑外形对数值计算结果的影响.     

Effect of spatial inhomogeneity of the resistance coefficient on the dynamics of the <Emphasis Type="Italic">M</Emphasis><Subscript>2</Subscript> tidal wave in the White Sea

To find variations in the dynamics of the surface M ₂ tide in the White Sea induced by the spatially inhomogeneity of the resistance coefficient, we use a modified version of the QUODDY-4 three-dimensional finite-element hydrostatic model. This version differs from the original version in that it has a module introduced to calculate the resistance coefficient in the bottom boundary layer (BBL). The resistance coefficient is found from resistance laws for an oscillating rotating turbulent BBL over hydrodynamically rough and partially rough (smoothly rough) underlying surfaces describing the dependence of the resistance coefficient and other integral characteristics of resistance on dimensionless similarity parameters: the sea-bottom Rossby number Ro, the streaming Reynolds number Re, and the relative (normalized to tidal frequency) inertial frequency f/σ. The use of spatial inhomogeneity of the resistance coefficient was shown not to lead to considerable changes in tidal characteristics. The values of these characteristics are several times larger than the instrumental measurement errors for the level and velocity but less than the errors in their calculation.     

Comparing the passive sampler and biomonitoring of organic pollutants in water: A laboratory study

Passive sampling could provide the solution to problems associated with costly and time consuming sampling programmes and biomonitoring. Mussels (Mytilus edulis) and Chemcatcher passive sampler were simultaneously analyzed for sequestered pesticides and polychlorinated biphenyls (PCBs) by gas chromatography with mass spectrometry (GC/MSD). The Chemcatcher passive sampler based on a solid phase extraction disc with two types of diffusion-limiting membranes (polyethelene and polysulphone), were also compared. Diuron, atrazine, irgarol and lindane were accumulated in the polysulphone passive sampler in greater concentration than in the mussels or in the other passive samplers with polyethelene limiting-membrane. Mussels can accumulate in their tissue high concentration of non polar compounds such as PCB 52, dieldren and PCB 153; more than the passive sampler with polysulphone membrane. The device with polyethelene limiting membrane has high affinity capacity to concentrate high amount of phenenthrene, dieldrin, PCB 153 and PCB 52, so it acts as a sampler for non-polar compounds. The highest uptake rate of hydrophobic compounds by Chemcatcher was observed for analytes with log octanol-water partition coefficient (K_OW) between 4.5 and 7.5. Laboratory-based studies using passive samplers to assess the potential for bioaccumulation could provide robust and reliable information at relatively low cost compared to biomonitoring data. Laboratory data obtained using passive samplers could be related to accumulation under field conditions where field assessments are required.     

用静力触探参数确定地基土水平地基抗力系数的比例系数m值--以天津地区为例

承受水平荷载作用的桩基,规范中常采用m法进行桩基水平承载力的计算,地基土水平地基抗力系数的比例系数m值在规范中根据地基土的状态、类别以表格给出。在地基勘察中,现在广泛采用静力触探试验。直接利用静力触探数据给出比例系数m值。将使桩基设计所用参数更加直接准确。本文利用天津地区地层大量静力触探资料与地基土状态数据,利用统计分析回归方法,总结出地基土的液性指数IL与静力触探参数锥尖阻力qc及摩阻比Rf间的关系式,针对天津的地层土体,给出利用静力触探资料查用m值的表格,为桩基的设计计算提供资料。     

桩列透空堤的水动力计算

分析了平面渡与桩列透空堤的相互作用.根据对矩形桩列上力平衡原理和非线性流阻等水动力学特征分析,导出一组计算反射、传递系数和波浪荷载的理论公式.计算公式内所有参数均是已知的,用它们预测的结果与现有的试验数据很好吻合.     

导管架夹桩器受力分析及液压缸数选择

夹桩器是海上导管架调平和灌浆的辅助工具。分析夹桩器受力及影响静摩擦系数因素,得出增大液压缸钳口表面粗糙度是增大钳口与钢桩间静摩擦系数的合理方法;并采用ANSYS有限元分析方法对夹桩器上均布液压缸数进行了选择。     

In situ filtration sampler for taking filtered water samples

A new type ofin situ filtration sampler is described. The all Teflon sampler is hung on a nylon rope attached to a steel wire (Fig. 3). By dropping a messenger, the sampler piston is pulled down by a released weight of 50 kg, and the sampler is filled with about 400 ml of filtered water. The sample is not contaminated by metals because there is no metal around the sampler.     

A comparative study of energy performance of hydrostatic seafloor sediment samplers and a new high-efficiency sampler

The hydrostatic energy of high-pressure seawater is a renewable and green energy source for ocean exploration and have been used to replace underwater electrical energy transmission through the cable and underwater battery pack to power seafloor equipment. The advantage of the energy supply method is the cost-effective and the robustness. In the paper, the energy performance of the existing hydrostatic seafloor sediment samplers powered by seawater hydrostatic energy are modelled and analyzed and compared. In view of the common shortcoming of existing technology, a novel hydrostatic seafloor sediment sampler is proposed. The model of energy conversion of the new sampler is built, and its energy performance is obtained. The analysis results indicate that the energy conversion efficiency of the novel sediment sampler is much higher than the existing ones, which means that the new sampler can collect much longer sample with the limited amount of hydrostatic energy. The seawater hydrostatic energy conversion system of the new sampler can also be used to power other seafloor equipment.     

Spar平台湿拖阻力性能研究

海洋平台由拖船拖至工作地点,计算海洋平台的湿拖阻力在实际工程应用中具有重要意义。采用实验和数值模拟两种方法进行桁架式Spar平台的湿拖阻力性能研究,并将两种结果进行对比。并分析了桁架式Spar平台的垂荡板间流场的变化规律。研究结果表明,Spar平台的湿拖阻力中,摩擦阻力所占总阻力的比例小于10%;在平台拖曳运动的前几秒中,垂荡板间流体剧烈运动,速度和压力显著变化,随后就运动慢慢变缓;Spar平台在低速拖曳时会产生明显的波浪,尾部有回流。     

固定式海洋平台极限强度试验研究

根据墨西哥湾某海域一典型固定式海洋平台为原型,按照几何相似准则和刚度相似准则设计并制作海洋平台试验模型,开展极限强度模型试验研究,观察并记录其破坏过程。并采用非线性有限元方法(ANSYS)对试验模型进行极限强度数值计算,将计算结果与试验结果对比,结果表明计算结果与试验结果吻合较好,验证非线性有限元方法的有效性。     

A Novel Mechanical Gas-Tight Sampler for Hydrothermal Fluids

A new mechanical gas-tight sampler has been designed to collect hydrothermal fluids at the seafloor. A key feature of the sampler is the novel sample valve which is pressure balanced under deep sea, and actuated by the ram on a submersible's manipulator. The sampler is designed to be deployed at the seafloor 3000 m underwater and can be used to sample hydrothermal fluid with temperature up to 400degC. Compressed gas is used to compensate for pressure reduction of sample fluids. Simulation of the flow system was conducted to estimate the fill rate. The sampler has been tested successfully in the first Sino-American Cooperative Deep Submergence Project from August 13 to September 3, 2005.