Bionic microchannels for step lifting transpiration

Those various cross-sectional vessels in trees transfer water to as high as 100 meters,but the traditional fabrication methods limit the manufacturing of those vessels,resulting in the non-availability of those bionic microchannels.Herein,we fabricate those bionic microchannels with various cross-sections by employing projection micro-stereolithography(PμSL)based 3D printing technique.The circumradius of bionic microchannels(pentagonal,square,triangle,and five-pointed star)can be as small as 100μm with precisely fabricated sharp corners.What's more,those bionic microchannels demonstrate marvelous microfluidic performance with strong precursor effects enabled by their sharp corners.Most significantly,those special properties of our bionic microchannels enable them outstanding step lifting performance to transport water to tens of millimeters,though the water can only be transported to at most 20 mm for a single bionic microchannel.The mimicked transpiration based on the step lifting of water from bionic microchannels is also achieved.Those precisely fabricated,low-cost,various cross-sectional bionic microchannels promise applications as microfluidic chips,long-distance unpowered water transportation,step lifting,mimicked transpiration,and so on.

Structure Analysis of Locking Mechanism of Gear-Rack Typed Ship-Lift

Contact nonlinear theory was researched. Contact problem was transformed into optimization problem containing Lagrange multiplier, and unsymmetrical stiffness matrix was transformed into symmetrical stiffness matrix. A finite element analysis （FEA） model defining more than 300 contact pairs for long nut-short screw locking mechanism of a large-scale vertical gear-rack typed ship-lift was built. Using augmented Lagrange method and symmetry algorithm of contact element stiffness, the FEA model was analyzed, and the contact stress of contact interfaces and the von Mises stress of key parts were obtained. The results show that the design of the locking mechanism meets the requirement of engineering, and this method is effective for solving large stole nonlinear contact pairs.

Finite element analysis on nut post structure of Three Gorges Project ship lift

A nonlinear finite element model of the nut post reinforced concrete (RC) structure of the safety mechanism in the Three Gorges Project (TGP) ship lift was built by ANSYS software. Some irregular structures such as the nut post and the rotary rod were divided by curved surface into a series of regular parts, and the structures were all meshed to hexahedron. Constraint equations were defined between two interfaces with different element sizes and mesh patterns. PRETS179 elements were used to simulate the preload in the tendons and the pre-stressed screws, and the loss of prestressing force was calculated. Five extreme load cases were analyzed. The stress of each part in the structure was obtained. The results indicate that the maximum compressive stress of concrete C35 is 24.13 MPa, so the concrete may be partially crushed; the maximum tensile stress of the grouting motar is 6.73 MPa, so the grouting motar may partially fracture; the maximum von Mises stress of the rotary rod is 648.70 MPa, therefore the rotary rod may partially yield.

Finite element and experimental analysis of pinion bracket-assembly of three gorges project ship lift

The pinion bracket-assembly(PBA) is a major part of three gorges project(TGP) ship lift drive system. The static strength,fatigue strength and stress distribution of hinge pin of PBA were analyzed by ANSYS, and the structure of PBA was optimized. The results show that after the optimization, the maximum comprehensive stress is 259.59 MPa, the maximum fatigue cumulative damage of weld joints is 0.94 and the maximum vertical deformation of hinge pin is 0.14 mm. The elastic deformation, hydropneumatic spring cylinder(HSC) load response and the vibration characteristics of PBA were studied by the bearing test when PBA bore the load caused by different water level errors. The results indicate that when the water level of ship chamber ranges from 3.4 m to 3.6 m,the vertical elastic deformation of the pinion shaft is between-8.58 and 10.50 mm. When upward outage-load(1580 k N) is imposed by the test-rack, the vertical elastic deformation of the pinion shaft is 13.42 and 14.07 mm and HSC load response is 795.80-800.80 k N. In the process of imposing load on the pinion by the test-rack, the maximum vibration amplitude and acceleration of PBA internal components are 0.37° and 2.67 rad/s2, respectively; the maximum impact on the pin caused by vibration is 19.89 k N; the pinion shaft vertical displacement and HSC load response do not fluctuate. There is a great difference between the frequency of meshing force of the pinion and the rack(1.06 Hz) and first-order natural frequency of PBA(8.41 Hz), thus PBA will not resonate.From all above, PBA meets the static strength and fatigue strength requirements. The vibration of PBA internal components has no effect on the vertical displacement of the pinion shaft, HSC load response and smooth operation of PBA. There is a liner relationship in the ratio of 2:1 between the thrust imposed by the test-rack and HSC load, thus HSC can limit the load imposed on the pinion.

Design and implementation of an expert system for remote fault diagnosis in ship lift

In this paper an expert system for remote fault diagnosis in the ship lift was developed by analysis of the fault tree and combination with VPN. The fault tree was constructed based on the operation condition of the ship lift. The diagnosis model was constructed by hierarchical classification of the fault tree structure, and the inference mechanism was given. Logical structure of the fault diagnosis in the ship lift was proposed. The implementation of the expert system for remote fault diagnosis in the ship lift was discussed, and the expert system developed was realized on the VPN virtual network. The system was applied to the Gaobaozhou ship lift project, and it ran successfully.

Analysis on Shock Wave Speed of Water Hammer of Lifting Pipes for Deep-Sea Mining

Water hammer occurs whenever the fluid velocity in vertical lifting pipe systems for deep-sea mining suddenly changes. In this work, the shock wave was proven to play an important role in changing pressures and periods, and mathematical and numerical modeling technology was presented for simulated transient pressure in the abnormal pump operation. As volume concentrations were taken into account of shock wave speed, the experiment results about the pressure-time history, discharge-time history and period for the lifting pipe system showed that： as its concentrations rose up, the maximum transient pressure went down, so did its discharges; when its volume concentrations increased gradually, the period numbers of pressure decay were getting less and less, and the corresponding shock wave speed decreased. These results have highly coincided with simulation results. The conclusions are important to design lifting transporting system to prevent water hammer in order to avoid potentially devastating consequences, such as damage to components and equipment and risks to personnel.

On Aircraft Lift and Drag Reduction Using V Shaped Riblets

Reducing drag during take-off and nominal(cruise)conditions is a problem of fundamental importance in aeronautical engineering.Existing studies have demonstrated that v-shaped symmetrical riblets can effectively be used for turbulence control,with those with dimensionless depth h+=15 and dimensionless width s+=15 having the best drag reduction effect.In the present study,experimental tests have been conducted considering two models of the same size,one with smooth surface,the other with v-shaped riblets of the h+=15 and s+=15 type.The results show that for an angle of attack in the 8°~20°range(take-off stage),the maximum lift coefficient can be increased by 22%.For angle of attack between 8°and 14°,a drag reduction effect can be produced using riblets,which increases with the Reynolds number,leading to a decrease in the drag coefficient maximum of 36%.Flow visualization experiments have been carried out by means of Laser Induced fluorescence.

DP Heavy Lift试验探讨

随着海洋开发的深入,目前市场需要更多的带动力定位(Dynamic Positioning,DP)系统的起重船,使得吊装工程业主方对DP模式下船舶的定位能力提出了越来越高的要求。国外某系统服务商已开发出动力定位模式下的吊重软件(DP Heavy Lift)及配套设备。因此,将重点说明一艘国内某型起重船在海上进行DP Heavy Lift试验的组织与实施,希望对后续同类型项目的 DP Heavy Lift海上试验具有一定的借鉴意义。

面向船舶吊装工艺安全评估的有限元快速建模方法研究

分段吊装是船舶建造中的一项重要工艺,为精准模拟船舶吊装作业过程中眼板结构节点的应力分布,在船舶吊装有限元强度计算时眼板区域需进行细网格计算.基于由几何方法添加辅助硬点并生成过渡单元的思路,提出了一种眼板有限元细网格快速生成方法.在粗网格的基础上,将眼板几何模型进行网格细化并根据布置位置与粗网格相连接.基于HyperMesh二次开发,编制了实用可靠的程序,提高了眼板的建模计算效率.

多种通航建筑物组合布置的通过时间研究

山区航道高水头通航建筑物多采用船闸、升船机、隧洞和中间渠道组合布置的形式。多种通航建筑物组合布置时,各通航建筑物的通过能力相互制约和影响,计算较为复杂。结合工程实际,在通过能力计算中,分析了通过各建筑物时间的匹配性及其对通航效率的影响,指出在组合布置通航建筑物时,应以船闸或升船机1次运行时间为基础,复核计算通航隧洞、辅助闸门等其他通航建筑物的1次运行时间是否小于基础时间,当大于基础时间时,应合理调整组合形式、布置形式和建设规模,成果可为类似工程提供参考。

大庆油田能效评价指标体系及能效综合评价方法研究

针对现行油田主要生产系统能效评价指标及其限值和评价方法对于大庆油田不完全适用的问题,根据工作内容,将油田生产系统划分为机采、集输、注水3个子系统;根据用能的关联性,将油田生产系统划分为机采集输和注水两个子系统,对于这两种子系统的划分,分别建立了能效评价指标体系。体系中的能效评价指标均分为系统级、单元级和设备级3个层级;明确了体系中各项指标的定义、计算方法、基础参数来源及统计口径。基于大庆油田实际情况,根据开采区块类型、驱替方式等,将测试数据进行分组,用统计方法确定每组各个能效指标的优良和合格限值;建立了单项与多项组合的油田生产系统加权能效综合评价方法,该方法综合考虑系统效率或系统单耗及其影响因素,在以较大权重计入系统级指标的同时,以较小的权重计入主要影响因素,即在要求系统指标的同时,也对单元级和设备级指标提出要求,从而分析评定所评价系统能效的提升空间。应用此评价方法对6个机采系统、1个集输和1个机采集输系统进行了能效综合评价。

旋转水力提升多金属结核运动特性数值模拟

采用CFD-DEM耦合方法对多金属结核提升进行模拟,研究了垂直管道中不同旋转流场旋流比对水力提升多金属结核输运特性的影响。结果表明,随着旋转流场旋流比增大,旋转强度显著增强,流体流速最大值增大,颗粒群轴向平均速度增大。旋转流场的旋转强度明显影响管道内颗粒的速度分布:速度大的颗粒逐步分布在管壁周围,速度较小的颗粒分布在管道中心处。旋转流场可降低颗粒群局部浓度,有利于降低因颗粒滞留效应引起局部浓度升高造成的输送管堵塞风险。

升船机电气传动系统应急运行研究

齿轮齿条爬升式垂直升船机一般采用四点均匀驱动承船厢升降,4套驱动装置通过同步轴系统刚性连接,正常工况下四个驱动点保持同步运行,同步轴受力很小。由于承船厢重量与平衡重重量基本一致,驱动装置处于轻载状态。在保证各驱动点电机不过载和同步轴力矩不超标的条件下,本研究项目旨在论证和试验在1套电气传动装置(电机+变频器)故障退出情况下,其余3套驱动装置能否继续运行,以提高升船机运行的整体可靠性。通过理论计算,在承船厢误载水深控制在±5 cm的范围内,3台电机的出力可以驱动承船厢运行。在对电气传动系统控制架构进行调整后,实现了任意一套传动机构退出后,其余3套驱动装置继续运行的功能,并且同步轴扭矩保持在允许范围内。

欧盟航运碳减排法规对多用途重吊船队的影响

针对多用途重吊船队,按照欧盟航运碳减排法规的具体方案,使用统计的方法和数据计算,准确预算船队在欧盟排放交易体系和欧盟可持续海运燃料法规实施10年内,因船舶燃料温室气体排放带来的成本增加量。通过分析欧盟航运碳减排法规中的各种关键要素,针对多用途船型特点,给出全方面的应对方案。

辅助搬运车辆电动化智能装备模型的设计

提供了一种辅助搬运汽车的设备,两个主体分别托举汽车的前轮和后轮,当汽车同根车轴上的两个车轮之间的距离窄时,通过伸缩机构收缩第一基座和第二基座之间的距离,令主体驶入底部,避免碰撞汽车车轮,通过伸缩机构延伸第一基座和第二基座之间的距离,使其更靠近汽车同根车轴上的两个车轮,令两个车轮施加给两个托举机构的受力点更加靠近第一基座和第二基座,提升托举机构的托举强度,避免汽车损坏托举机构。托举机构调节机构滑动设计使得要搬运的汽车车轮尺寸较大或较小时均能调整两个相邻托举机构之间的距离,更稳定地托举轮胎。

“矿山提升与运输”课程思政教学探索

课程思政是思政课程的进一步深化与有力补充,全面推进课程思政建设是落实立德树人根本任务的战略举措。因此,对于采矿工程专业而言,根据采矿工程专业特点大力开展专业类课程的课程思政建设对于培养新时代优秀采矿专业人才具有非常重要的意义。本文根据“矿山提升与运输”课程内容特点和采矿工程专业特点,深入挖掘了“矿山提升与运输”课程思政元素,并对课程思政教学实施方式进行了积极的探索。本文研究成果可为地矿类专业类课程思政建设提供参考与借鉴。

增建升船机恢复海河航运功能的设想

通过对海河通航及旅游业发展现状的分析,提出在保持二道闸现有功能和结构的前提下,可考虑在此处修建升船机,打通海河下游航道,使得游船可通过二道闸,实现海河全线通航,后续可带动海河沿岸服务产业和货运运输,以此促进天津航运经济发展。

基于改进NSGA-Ⅱ的破损沉船起吊力优化

沉船打捞工程中,按照工程经验布置的起吊力参数(位置和大小)容易使得破损沉船起吊时的内力(剪力和弯矩)较大,可能导致沉船起吊断裂,尤其当沉船存在破损时,起吊断裂的可能性大大增加。为此,从梁弯曲理论出发,针对沉船起吊时的受力特点建立了以起吊力参数为输入,以内力分布为输出的沉船内力数值计算模型;基于该计算模型,以起吊力参数为优化变量,以内力峰值为优化目标,建立了起吊力参数优化模型;采用改进的NSGA-Ⅱ算法进行优化计算。以某破损沉船为对象,通过MATLAB实现建模与优化计算,结果表明:优化后的剪力峰值下降约22.72%,弯矩峰值下降约16.13%。

升船机全生命周期BIM应用研究

目前对于通航建筑物的BIM技术应用通常局限于设计或者施工等单个阶段,缺乏对其全生命周期的BIM应用。以某升船机工程为例,将BIM技术引入其设计、施工、运维的各个阶段。在设计阶段,基于Bentley平台对升船机进行了三维模型搭建,在此基础上应用ANSYS对其进行了有限元数值仿真,应用Lumion对其进行了可视化虚拟仿真;在施工阶段,利用Microsoft Project和Synchro Pro进行了施工进度管理和施工仿真模拟;在运维阶段,借助IDEA编辑器、VSCODE软件和MySQL等软件进行代码编写,构建了基于BIM技术的智慧运维管理平台。实践表明:在升船机全生命周期中运用BIM技术,提高了设计的准确性和协同性,加强了施工的协调性,运维管理平台的搭建实现了BIM模型展示、升船机水位和状态监测等功能,为升船机运维管理提供了决策支持。研究成果可为BIM技术在类似水利工程设计、施工、运维等全生命周期的应用提供参考。

邮轮上层建筑分段吊装评估与参数敏感性分析

针对邮轮上建采用的钢板较薄,且舷侧大开孔密集,结构刚度较弱,在上建吊装过程中容易出现结构或者舾装件损伤的问题,总结邮轮上建分段吊装的评估流程,以一极地邮轮上建分段为例,开展吊装方案设计,并利用有限元对结构应力、分段整体位移与舷侧开孔局部位移进行计算评估,利用线性回归方法对吊装参数进行敏感性分析,结果表明,邮轮上建舷侧结构的局部相对位移评估十分有必要,相对于应力和整体位移,为主控因素,且垂向位移是局部位移评估的主控参量;结构应力与开孔局部位移对吊耳布置更敏感,整体位移对临时补强更敏感。