Arc additive manufacturing of gradient hot forging die with shaped waterways

Under the working environment of high temperature and strong load impact,hot forging die is prone to failure which reduces the service life of die.Using arc additive manufacturing in the die cavity,a gradient material hot forging die with high precision,superior per-formance,and conformal cooling channels is developed.This improves the toughness of the die cavity and reduces the working temperature,thereby forming an isothermal field,which is an effective method to enhance the lifespan of the hot forging die.Three kinds of gradient flux-cored wires are designed for the surface of 5CrNiMo steel,and the microstructure and mechanical properties between gradient interfaces were studied.Based on the spatial curved structure of shaped waterways in the hot forging die cavity,a study was conducted on the strategy of partitioned forming for the manufacturing of the die with shaped waterways.In order to avoid interference with the arc gun,the hot for-ging die is divided into four regions,namely the transition region,upper,middle,and lower region,based on a combination of cavity depth and internal U-shaped and quadrilateral structures.The results show that the developed flux-cored wires have good moldability with straight sides of deposited metal under different process parameters and flat surface without cracks,pores and other defects.Under the same working conditions,the life of hot forging die formed by the gradient materials is more than multiple times that of the single material hot forging die,and the temperature gradient field of the shaped waterway die is 7℃/cm smaller than that of traditional straight waterway.

桃源枢纽河段通航水流条件数值模拟

针对桃源枢纽船闸存在的碍航问题,以沅水桃源枢纽二线船闸建设工程为项目依托,采用二维动力学数值模拟方法对桃源枢纽—周文庙水文站河段通航水流条件进行研究。基于对多工况水深、水位、流速等参数的分析,进而研究枢纽与坝下航道的通航水流条件和碍航滩段,并根据滩险问题提出挖槽疏浚等航道整治措施。结果表明:在现有地形条件下工况1(Q=217 m^(3)/s)和工况2(Q=380 m^(3)/s)在距桃源枢纽0~20 km河段和80~95 km河段碍航问题突出,当流量大于工况3(1 233 m^(3)/s)时满足Ⅲ级航道尺度要求。经数学模型验证,对碍航滩段进行拟定的挖槽疏浚等措施能够有效改善航道的通航水流条件。

Analysis of Landscape Design of the Visual Aids to Navigation of Inland Waterway

The visual navigation marks are established purposely,which transfer information to the trained observer in order to navigate.The visual aids to navigation in freshwater could give aid to navigation.In addition,through its basic shape,appearance forms and colors,the landscape of navigation waterway is also displayed.The aids to navigation together with channel revetment and other surrounding landscape elements determine the landscape effect of the navigation waterway.Through analyzing the design of aids to navigation features,the design impact factors,the landscape design principles and methods of treatment are proposed in this research,in order to provide some references for the design of future visual aids to navigation.

临水之亭与东汉临湘地区的水路管理

五一简所见东汉临湘地区的临水之亭,既包括㢕亭、庾亭、阳马亭、西市亭、南亭等在内的正式设立的亭,也有沂口例亭、楮溪例亭、■溪例亭、横溪例亭、欣例亭与漻例亭等灵活设置的例亭。临水之亭沿湘水与临湘内河分布,其中例亭所临河流基本上为临湘内河,这样的分布格局是由湘水水道与临湘内河不同的治安环境决定的。临水之亭的水路管理职能,主要体现在检查登记、维护治安与协助征税3个方面,在东汉基层社会治理中发挥着重要作用。

柳江Ⅱ级航道工程可行性研究

柳江Ⅱ级航道作为西南水运出海北线通道的重要组成部分,但运力不足。根据整治河段自然资源分布、社会经济发展与工业布局现状及规划、航运发展前景对建设柳江Ⅱ级航道进行可行性研究。建立柳江Ⅱ级航道设计标准和设计原则,依据通航率和航道等级,提出一种计算航道尺寸的方法,并基于柳江Ⅱ级航道工程设计最低通航水位和河段分期水位-流量计算柳江Ⅱ级航道流量,根据Ⅱ级航道弯曲半径的要求及使用和维护的便利性,提出滩段航道线路方案,实现全长173 km的2 000吨级Ⅱ级航道建设,根据运量预测2025、2035、2050年货运量分别为2 670万、4 810万、6 500万t。

基于无人机图像的内河航道养护异常事件识别研究

随着内河航道的不断疏浚扩展,传统航道养护巡检业务模式已日渐暴露即时性差、触达率低等问题。为有效解决相关问题,首先,本文综合分析江苏省内河航道养护巡检业务现状,创新性地将无人机图像与人工智能巡检技术相结合。随后,基于YOLO卷积神经网络构建目标识别算法,对临河施工、护岸毁损等重点航道养护异常事件实现精准识别。研究可为内河航道养护智能巡检提供应用示范,为水运高质量发展提供技术参考。

Possibilities and challenges of expanding dimensions of waterway downstream of Three Gorges Dam

The waterway in the middle and lower reaches of the Yangtze River has long been known as the Golden Waterway and has served as an important link in the construction of the Yangtze River Economic Belt.Therefore,expanding its dimensions is a significant goal,particularly given the long-range cumulative erosion occurring downstream of the Three Gorges Dam (TGD),which has been concentrated in the dry river channel.With the regulation of the volume from upstream reservoirs and the TGD,the minimum discharge and water level of the river downstream are increasing,and creating favorable conditions for the increase of the depth of the waterway.The discharge compensation effect during the dry season offsets the decline in the water level of the river channel caused by the down-cutting of part of the riverbed,but the minimum navigable water level of the segment near the dam still shows a declining trend.In recent years,several waterway remediation projects have been implemented in the downstream reaches of the TGD and although the waterway depth and width have been increased,the channel dimensions are still insufficient in the Yichang-Anqing reach (with a total length of 1026 km),as compared to the upstream reservoir area and the deep water channel in the downstream tidal reaches.A comprehensive analysis of the water depth and the number and length of shoals in the waterway indicates that its dimensions can be increased to 4.5 m ×200 m and 6.0 m×200 m in the Yichang-Wuhan and Wuhan-Anqing reaches,respectively.This is also feasible given the remediation technologies currently available,but remediation projects need to be coordinated with those for flood prevention and ecological protection.

Heavy Metal Pollution and Ecological Risk Assessment in Sediments of Xiling Channel Inland Waterway of Guangdong Province

Using the sediment monitoring data of five sections of the Xiling Channel inland waterway of the Pearl River Delta,and using Nemerow composite index,the coefficient of variation,and the index of geoaccumulation( Igeo) and the potential ecological risk index,this paper analyzed and assessed the heavy metal pollution of sediments. The results indicate that Cr reached mild pollution;Cu had a large degree of variation,and the changes of Cr and Zn were significant with fluctuation;the enrichment of heavy metals decreased as follows: Cd > Cu > Cr > Zn> Pb > Ni > Hg > As;Cd had the highest degree of enrichment and belonged to moderate pollution;the ecological hazard of heavy metals was Cd > Hg > Cu > Pb > As > Cr > Ni > Zn,and Cd had the highest ecological hazard and was the main controlling factor of potential ecological risk. In conclusion,the sediments in Xiling Channel inland waterway were polluted by heavy metals to some extent,and cadmium was the main pollutant and had the largest potential ecological risk.

基于GNSS三维水道观测技术的水深测量

为了探究GNSS三维水道观测技术在长江中游及汉江中下游水深测量精度问题,基于国内外目前水深测量研究现状,阐述了传统验潮模式与GNSS三维水道观测模式两种水深测量基本原理,通过Hypack软件获取GNSS动态测高数据,对试验区内两种模式下水深测量数据的精度进行了详细分析。结果表明:测区内分段高程转换模型精度与GNSS定位精度均为良好。GNSS三维水道观测数据与验潮数据相比,水位互差小于0.1 m的测点占比大于95%,满足相关行业规范要求,证明GNSS三维水道观测技术在长江中游及汉江中下游河段具备一定可靠性和精确性,可进一步推广应用。

Physical Modeling of Localized Scour for the Yangtze Estuary Waterway Improvement Project,Phase Ⅰ

In order to examine the effectiveness of engineering protection against localized scour in front of the south groin-group of the Yangtze Estuary Waterway Improvement Project, Phase I , an undistort-ed physical model on a geometric scale of 1:250 is built in this study, covering two groins and their adacent estuarine areas. By use of rinsing fix-bed model as well as localized mobile-bed model, the experiment is undertaken under bi-directional steady flow. According to the experimental results, waterway dredging leads to the increase in steram velocity, the increase being larger during the ebb than during the flood. Construction of the upstream groin has some influence on the flow patterns near the downstream groin. Localized scour in front of the groin-heads is controlled mainly by ebb flow. In the case of a riverbed composed entirely of silt, the depths of localized scour in front of the two groin- heads are 27 m and 29 m, respectively. In reality, the underneath sediment of the prototype riverbed is clay whose threshold velocity is much higher than the stream velocity in the Yangtze Estuary; therefore, the depths of localized scour will not be much larger than the thickness of the silt layer, i. e. 7.4 m and 4.7 m, respectively. The designed aprons covering the riverbed in fron of the groin-heads are very effective in scour control. Aprons of slightly smaller size can also fulfill the task of protection, but the area of localized scour increases significantly.

The Use of Hydrogen as a Fuel for Inland Waterway Units

Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.

How Waterways, Glacial Melt Waters, and Earthquakes Re-aligned Ancient Rivers and Changed Illinois Borders

The borders of Illinois were established when Illinois became a state in 1818. The western border was delineated using the Mississippi River, and the Ohio River was used as the southern border. The eastern border was formed by the Ohio and Wabash Rivers plus the line along latitude 42030＇30＇＇ connecting the Wabash River to Lake Michigan. As initially proposed, the northern border of Illinois would have been 82 km （51 mi） to the south of the current longitude line of 87~31 ＇. This 2,160,000 ha （5,440,000 ac） addition to Illinois resulted in the territory having the required minimum of 40,000 people to qualify as a state. The northern border was moved to allow the linkage of the Great Lakes shipping route to the Illinois and Mississippi River navigation channels. Illinois thus gained a valuable shoreline on Lake Michigan and a location for a shipping port hub which became Chicago. Initially the transfer of goods between these waterways required a portage, but later a shipping canal was created to link the waterways. During the Civil War, Union forces used the connected waterway systems as a northern supply route to avoid the contested Ohio River.

A Study on Conversion of Marine Diesel Engines Using Blended Palm Oil for Inland Waterway Vessels in Vietnam

The climate change and limitation of natural resources becomes main obstacle for the global economical development. So, the Vietnamese Government is very much concerned with reduction of harmful gas discharging from the inland-water way ships. To overcome the problems, there are many counter-measures proposed such as： renovation of machinery and equipment, using re-creative energy and so on. The author＇s idea is to find a suitable method which can be applied on board of the inland-water ships to reduce discharging toxic gas by using blended palm oil as alternative fuel for marine diesel engines. Due to some disadvantages of the bended palm oil in comparison with traditional DO （diesel oil）, such as： low freezing point, high viscosity, low stability of blended fue, therefore somehow, the blended palm oil must be made a ship directly on board. With this idea, the author has designed and made agitate mixing equipment working on-line with fuel supply system of a diesel engine. The mixing equipment, then, has been tested at shore-side laboratory as well as on board ships. The research results showed that the fuel mixture （palm oil-DO） made by this mixing equipment is fully usable to replace traditional DO for marine diesel engines installed on board ships of inland water way in Vietnam. The Vietnamese Government accepted the research results as prerequisite to devise specific and practical action plans to reduce the pollution from the inland water way ships in coming years.

The study on a new technology of waterway information system

It is a lot limitations to survey and design waterway by the CAD technique, due to timely variation of hydrology and ecology in the complicated estuary area, such as Changjing River estuary. In this paper, the advantages of GIS technique is applied to manage and process the multi kind , multi scale and multi time hydrographic parameters, including water depth, current velocity, tidal, waves, wind speed, temperature and salinity etc., also to deal with different projection, different scale charts. Meanwhile, in the paper, combination techniques of GIS and CAD has been developed for unification of the charts for efficient management, two-way automatic carts conversion between GIS and CAD, automatic cutting and assemble of a number of Charts, flight path of the projection of spatial data and coordinate transformation. This new technique has been applied to survey and design waterway of Changing River estuary. The result shows that the combination technology of GIS and CAD has application potentiality in the waterway survey and design.

Study on the Improvement of Sea-Entering Waterway in the Changjiang Estuary

The Changjiang Estuary is the doorway of the Shanghai Harbour and the throat for the six provinces in the Changjiang River drainage area. However the minimum water depth of the waterway in the estuary is only about six meters, so that the development of the Shanghai Harbour and the utilization of water transportation on the Changjiang River have been greatly restrained. Since 1975, the depth of the sea-entering waterway of the Changjiang Estuary has been successfully increased by one meter. This article has made a comprehensive summing-up about the selection of waterways, the determination of the line for dredging and disposal of the dredged material, thus providing reference data for future work in increasing the depth of the waterway of the Changjiang Estuary and for controlling similar waterways of other estuaries.

Numerical Simulation of Abnormal Wave Height Change Induced by Excavated Waterway with Boussinesq Equation

A nonlinear numerical model has been set up by use of Boussinesq Equation with finite difference method, and has been applied to the simulation of the abnormal change of wave height induced by excavated waterway. Numerical results demonstrate that the abnormal change of wave height is due to the adding of the reflected wave height induced by excavated waterway to the incident wave height. Because the angle between the incident wave and the axis of the waterway is smaller than the critical angle, the reflected wave produced by the waterway may propagate to the breakwater and may be added with the incident wave, then the abnormal change of wave height before the breakwater may be caused. So the wave reflection caused by the change of water depth cannot be neglected.

INFLUENCES OF THE FISH-MOUTH PROJECT AND THE GROINS ON THE FLOW AND SEDIMENT RATIO OF THE YANGTZE RIVER WATERWAY

A depth_integrated two_dimensional numerical model of current, salinity and sediment transport was proposed and calibrated by the observation data in the Yangtze River Estuary. It was then applied to investigate the flow and sediment ratio of the navigation channel, i.e. the North Channel of the Yangtze River Estuary,before and after the first phase waterway project is implemented. Particularly, the influences of groin length and the orientation of the submerged dam on the flow ratio and sediment load discharging into the North Channel were discussed. The numerical results demonstrate that less sediment load discharges into the navigation channel, which unburdens the waterway dredging, but in the meantime the flow ratio is also decreased. The flow and sediment ratio can be adjusted by changing layout and dimensions of the hydro_structures, such as the groin length, the top height, etc. The effect of the orientation of the submerged dam is more obvious than the groin lengh.

Numerical Prediction of Hydrodynamic Forces on A Berthed Ship Induced by A Passing Ship in Different Waterway Geometries

An investigation has been conducted to quantify the effect of waterway geometry on the form and magnitude of forces and moment experienced by a berthed ship due to a passing ship.By using the dynamic mesh technique and solving the unsteady RANS equations in conjunction with a RNG k？ε turbulence model,numerical simulation of the three-dimensional unsteady viscous flow around a passing ship and a berthed ship in different waterway geometries is conducted,and the hydrodynamic forces and moment acting on the berthed ship are calculated.The proposed method is verified by comparing the numerical results with existing empirical curves and a selection of results from model scale experiments.The calculated interaction forces and moment are presented for six different waterway geometries.The magnitude of the peak values and the form of the forces and moment on the berthed ship for different cases are investigated to assess the effect of the waterway geometry.The results of present study can provide certain guidance on safe maneuvering of a ship passing by a berthed ship.

Linking Watershed Scales through Altered Waterways

Nested hierarchy theory advances the idea that rivers have a fractal dimension where processes at the catchment scale (>1 km) control processes at the reach or mesoscale (100 m) and microscale (1 - 10 m). Largely absent from this work is a mesoscale link to the larger and smaller scales. We used stream alteration classifications to provide this link. We used orthophotographs, land cover, and LiDAR derived terrain models to classify stream alterations within four watersheds. We compared phosphorus point data with watershed, sub-watershed, and 100-meter buffers around the point data. In the predominately urban watershed, the 100 m buffer scale correlated better with phosphorus levels. In the predominately agricultural watershed, the sub-watershed scale correlated with phosphorus levels better. We found adding the classification of the stream alteration type clarified anomalously low phosphorus levels.

Modelling Dry Port Systems in the Framework of Inland Waterway Container Terminals

Overcoming the global sustainability challenges of logistics requires applying solutions that minimize the negative effects of logistics activities.The most efficient way of doing so is through intermodal transportation(IT).Current IT systems rely mostly on road,rail,and sea transport,not inland waterway transport.Developing dry port(DP)terminals has been proven as a sustainable means of promoting and utilizing IT in the hinterland of seaport container terminals.Conventional DP systems consolidate container flows from/to seaports and integrate road and rail transportation modes in the hinterland which improves the sustainability of the whole logistics system.In this article,to extend literature on the sustainable development of different categories of IT terminals,especially DPs,and their varying roles,we examine the possibility of developing DP terminals within the framework of inland waterway container terminals(IWCTs).Establishing combined road–rail–inland waterway transport for observed container flows is expected to make the IT systems sustainable.As such,this article is the first to address the modelling of such DP systems.After mathematically formulating the problem of modelling DP systems,which entailed determining the number and location of DP terminals for IWCTs,their capacity,and their allocation of container flows,we solved the problem with a hybrid metaheuristic model based on the Bee Colony Optimisation(BCO)algorithmand themeasurement of alternatives and ranking according to compromise solution(i.e.,MARCOS)multi-criteria decision-making method.The results from our case study of the Danube region suggest that planning and developingDP terminals in the framework of IWCTs can indeed be sustainable,as well as contribute to the development of logistics networks,the regionalisation of river ports,and the geographic expansion of their hinterlands.Thus,the main contributions of this article are in proposing a novel DP concept variant,mathematically formulating the problems of its modelling,and developing an encompassing hybrid metaheuristic approach for treating the complex nature of the problem adequately.