内河离港船舶吃水在线动态扫描检测方法

船舶“超吃水冶引起的船舶搁浅事故呈逐年增多的趋势,对内河离港船舶吃水进行实时测量尤为必要. 针 对内河航道的特点,提出了一种利用单波束声收发分体传感器同步对船舶底部边缘进行扫描测量的方法,研究 了传感器系统构成,并对测量原理进行了理论推导. 设计了比尺为1100 的吃水测量试验系统,利用3 000 t级 小比尺船模按4 种工况进行试验,结果表明,船舶航速对船舶吃水测量值有一定影响,但最大误差仍控制在 11. 4%以内,证明了这种测量方法的可行性.     

长江口深水航道通航尺度核定测量精度研究

长江口12. 5 m深水航道自开通以来,已经成为了大型船舶进出长江黄金水道的重要通道,其维护测量通常采用单波束月度检测方式。影响单波束水深测量成果数据精度的因素很多,其中测量船舶换能器静吃水不准确也是重要原因之一。提出一种新型的测量船舶换能器静吃水精确测定方法,以提高实际工作中的水深测量成果精度。     

升船机内船舶吃水检测系统研究

在长江三峡升船机船舶试通航阶段,吃水安全检测依旧使用人工读取水尺的方法,效率偏低且精度不高,为此设计了一套基于STM32与FPGA双核结构的下位机系统和基于MFC的上位机预警软件系统。该系统主要依据水下超声波的传播模型和超声波的衍射效应,结合实时水位变动信息,采集得到通航船舶吃水量的点阵数列,最后计算得出通航船舶的吃水深度。通过在三峡升船机的现场实验和国家计量院的认证,证实该系统具有安装检修方便、实时性高等优点,测量吃水量与船舶水尺的对比差小于0.08 m。     

船舶对明渠水流运动的影响模型试验研究

为了探求船舶对于明渠水流运动的影响,利用水位测针和粒子图像测速(Particle Image Velocimetry, PIV)系统分别测量了明渠水流中不同吃水工况下船舶前、后的沿程水深及流场,分析了位于船舶中间纵剖面上的流速分布特征。结果表明：(1)相较于无船工况,船前水深略有增加,船后水深略有减少;且船舶对水深的影响程度随着吃水深度的增加而增加,有船与无船水深的比值最大为1.071,最小为0.951;(2)船舶中间纵剖面上纵向垂线流速分布从船头前“J”型向船舶底部的“?”型转变,流经船尾后逐渐恢复为“J”型,且在船头附近形成下潜水流、船尾附近形成上升水流;(3)在船舶吃水深度为0.6h时,纵向(沿水流方向)与垂向(沿水深方向)上都出现各个工况下的最大流速,纵向流速最大值达到无船时平均纵向流速的2.11倍,位于船头附近(x/l=-2/5);下潜水流流速最大值达到无船时平均纵向流速的71%,位于船头附近(x/l=-0.5);上升水流流速最大值达到无船时平均纵向流速的29%,位于船尾附近(x/l=2/3)。     

船舶上滩的影响因素及动水特性试验

在急流滩地形概化了的试验水槽中，进行了多种水力条件下的船模上滩试验．试验结果表明，滩段的水面比降、水流速度及船舶水深吃水比是船舶上滩的主要影响因素．     

流体黏性对迎浪航行船舶运动和波浪增阻的影响

对在规则波中迎浪航行的大型油轮KVLCC2船模,为了研究流体黏性对船舶运动和水动力的影响,分别采用求解RANS方程和求解欧拉方程的方法,应用CFD软件STAR-CCM+对黏性流场和无黏流场进行了数值模拟。采用GCI方法对数值不确定度进行了分析,验证了数值方法的有效性;采用湍流模型和无黏流模型对船舶在一系列波长的波浪中的运动和水动力进行了数值预报,并将数值结果与现有实验数据进行了比较。结果表明,流体黏性对船舶运动影响很小,对共振状态附近的波浪增阻有一定的影响。总体上,对船舶迎浪航行流场的数值模拟,忽略黏性能保证一定的计算精度而提高计算效率。     

基于自编码网络的海上风电机组典型故障诊断方法

当前海上风电机组故障诊断大多只利用SCADA系统数据或振动监测系统数据中一种数据源,诊断精度较低。为此,提出一种基于自编码网络的海上风电机组典型故障的数据融合诊断方法。首先,采用自编码网络分别对SCADA系统数据和振动监测数据的故障特征降维,并将二者融合。然后,采用两类故障特征融合的深度自编码网络故障诊断模型对典型故障进行检测及分类。最后,通过实际运行案例验证了本文提出的深度自编码网络故障诊断模型的有效性。     

傅里叶算法和微分方程算法的改进

本文对傅里叶算法作了改进。傅里叶系统并联一个适当的滤波器以后可以消除非周期分量对阻抗计算的影响。同时采用变动数据窗的方法，算法的响应时间显著地减少了而精度仍然得到保证。在本文中，对微分方程算法也作了探讨和改进。采用梯形法近似积分以及补偿系数的方案，提高了X的精度2%。又用数字滤波器模拟了模拟滤波器，对本方案R·X的误差作了分析，并采取了相应用对策。改进后的算法在DJS-131小型机上作了考核，并且编制了实时程序在INTEL-8086微型机上作了试验。结果是令人满意的。     

动态电压恢复器的复合数字多变量状态空间反馈控制

在三相三线制系统中，动态电压恢复器面临的主要控制问题是不平衡暂降下对系统三相不平衡的补偿问题。通过正负序分量分解并在正负序坐标下进行建模和控制的方法虽能较好地抑制三相不平衡，但由于正负序分解带来的延迟具有较慢的动态响应速度。为此，文中提出了一种复合数字多变量状态空间反馈控制的方法。在检测到暂降发生并在之后的一段时间内采用单数字多变量状态空间反馈法进行控制，进入稳态时通过控制量的分解无缝地切换到双数字多变量状态空间反馈法，检测到暂降结束时再无缝地切换到单数字多变量状态空间反馈法。该方法同时实现了较快的动态响应速度和较高的稳态精度。实验结果证明了该控制方法的有效性和可行性。     

河道安全巡检中的船舶可视化监测方法

针对河道安全巡检中的船舶可视化监测难题,基于高分辨率彩色图像识别技术,提出了一种河工模型试验中船模运动轨迹可视化测量方法和一种基于无人机的河道船舶轨迹跟踪方法。试验结果表明,船模运动轨迹可视化测量方法的测量值与实际值之间的最大相对误差为-3.284%,精度可以满足河工模型试验要求;船舶轨迹跟踪中采用加速稳健特征变换(SURF)方法对无人机图像进行配准,能有效地消除无人机位置飘移对船舶运动轨迹跟踪结果的影响,实现河道中多个船舶目标的运动轨迹同步可视化跟踪监测。     

A three-dimensional hydroelasticity theory for ship structures in acoustic field of shallow sea

Nowadays the development of green ship technology requires the vibration and noise control of oceangoing ships. The three-dimensional hydroelasticity theory of ships was previously extended to include the effect of fluid compressibility. This enables the dynamic responses and the acoustic radiations of a ship excited by onboard machineries or fluid fluctuation loads to be predicted. In this paper the hydroelastic analysis and sonoelastic analysis methods are fixrther incorporated with the Green＇s function in the Pekeris ocean hydro-acoustic waveguide model to work out a three-dimensional sonoelastic analysis method for ships in the ocean hydro-acoustic environment. As examples, the sound radiations of a floating elastic spherical shell excited by a concentrated force and a traveling LNG ship excited by the propeller induced pulsating forces acting on the wetted bottom plate of the stem in the shallow sea environment are predicted. The influences of the free surface and the sea bed on the generalized hydrodynamic coefficients and the acoustic pressure distributions in fluid domain are illustrated and discussed.     

Evaluation of the Effectiveness of a Living Shoreline in a Confined,Non‐Tidal Waterway Subject to Heavy Shipping Traffic

River bank erosion is a point of concern along navigable waterways because it increases the likelihood of bank failure. In non‐tidal and restricted fetch waterways, bank failure is mainly the result of extreme weather events and ship wave action. To counteract progressive bank erosion, nature‐friendly bank protection (a ‘living’ shoreline) has been installed in a stretch of the Lys (Belgium). It consists of off‐bank timber piling, which separates the fairway from the shallow water riverine environment, and a reed belt, planted at the base of the vertical cut bank. To evaluate its effectiveness, short‐term and long‐term field studies were carried out. The long‐term topographic survey did not reveal a clear difference in bank erosion rates between the surveyed nature‐friendly protected and naturally eroding embayments. Horizontal bank retreat could however not be linked directly to occasional flooding events and frequent ship wave action, although the latter's influence was inferred qualitatively. Based on velocity and turbidity measurements, the short‐term study pointed out the importance of an individual ship's wave action on bed and bank erosion behind the off‐bank timber piling. All ships were able to resuspend sandy bed sediments; yet, only a significant higher sediment volume was transported because of shipping traffic of the European Conference of Ministers of Transport (ECMT) classes IV and Va. If ship wave energy exceeded 45 Jm^?2, silty bank particles were dislodged from the river bank. Although validation of the results by longer term assessments may complete the physical insight in river bank erosion, the study indicated that this particular bank protecting configuration does not provide sufficient protection against ship wave action and does not adequately prevent further bank erosion. Copyright © 2014 John Wiley & Sons, Ltd.     

水面舰船气泡尾流的电导率特性和热特性的实验研究

在实验室水槽中用微孔陶瓷管模拟了水面舰船的气泡尾流，采用自制的包含电导率探头和温度传感器的复合探头，测量了模拟气泡尾流的电导率信号，并在海上实测了不同水面舰船气泡尾流的电导率信号和热特征信号，分析了这两种信号的形成机理及其主要影响因素。实验测量结果表明：水面舰船气泡尾流区的电导率信号和热特征信号与非尾流区的信号具有显著差别，尾流区与非尾流区的信号差值与海洋垂直温度梯度的大小、目标船的吨位和吃水深度及航速的大小成正比。     

嘉陵江草街船闸上游引航道水力学问题研究

嘉陵江草街船闸闸室尺寸为200.0 m×23.0 m×3.5 m(长×宽×门槛水深),最大工作水头26.7 m,其综合水力指标居我国已建单级船闸前列.施工期通航上游水位192.0 m,此时其上游引航道水深仅为2.9 m,如果阀门按设计指标正常开启,船闸灌水时上游引航道非恒定流特征明显,浮式导航墙存在较强斜流和漩涡,引航道水面比降及纵向流速较大,危及船舶通航安全,此外船闸进水口淹没深度较小,流量达到一定值时将出现较强漩涡,严重时还会出现贯穿吸气漩涡,影响闸室船舶安全.通过原型调试结合数学模型计算,解决了草街船闸施工期通航上游引航道特殊水力学问题,确定了船闸施工期通航运行方式,保证了船闸施工期通航安全运行.     

基于遗传算法的三峡-葛洲坝船闸闸室编排算法

三峡升船机的投入运行以及多线梯级联合调度环境的改变,给三峡升船机与船闸联合调度问题提出了新的挑战,其中闸室编排是求解三峡升船机与船闸联合调度问题的重要组成部分。在借鉴目前已有传统算法的基础上,提出了基于遗传算法的三峡-葛洲坝船闸闸室编排算法,并介绍了编码表示、选择策略、杂交算子和变异操作过程。选取三峡-葛洲坝船闸2015年4月船舶流数据进行测试,比较本文提出算法与实际人工处理产生的闸室编排以及待闸时间结果,验证了该算法的有效性和实用性。     

船舶进出闸室对系缆力的影响

船舶进、出闸室时,船行波在闸室内引起较大水面波动,造成闸室内系缆船舶的系缆力增大,影响闸室内的船舶停泊安全;大型船舶进、出闸室时,产生的船形波作用更强,对系缆船舶的系缆力影响更大。通过1∶36.3三峡船闸的物理模型和相同比尺5 000 t级典型大型船舶模型,采用系列物理模型试验,对船舶进出船闸时闸室内系缆船舶的系缆力进行了研究。研究结果表明,闸室内有系缆船舶时,船舶进、出闸的航行速度对系缆船舶的系缆力影响很大,进、出闸速度越快,其系缆力也越大。三峡船闸中,当水深5.5 m,闸室内有系缆船舶,大型船舶偏航进、出闸室时,为保证船舶停泊安全,航行船舶的进、出闸速度宜小于0.5 m/s。     

Characterizing ship-induced hydrodynamics in a heavy shipping traffic waterway via intensified field measurements

Ship-induced hydrodynamics play an important role in shaping the cross-sectional profile of inland waterways and produce a large amount of pressure on the fluvial environment. This study aimed at quantifying the characteristics of ship-induced waves and currents in a heavy shipping traffic waterway via intensified field measurements conducted in the Changzhou segment of the Grand Canal, in Jiangsu Province, China. Based on the processed hydrodynamic data, waves and currents caused by single ships and multiple ships were investigated. For single ships, the ship-induced wave heights estimated with empirical formulas were not consistent with the observations. Categorized by the loading conditions of barges, the drawdown height was characterized by the ratio of ship speed to its limit speed. The maximum non-dimensional ship-induced wave height was parameterized by a nonlinear combination of the depth Froude number and a blockage coefficient. For multiple ships, when ships closely followed each other or interlaced each other's paths, it was difficult to characterize the superposition of several ship wakes. The magnitudes of current velocities induced by single ships and multiple ships were respectively nine and six times as large as those of natural flow. This may result in more severe sediment (re)suspension than natural flows.