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simulation of wave scattering over a floating platform in the ocean with a coupled CFD-IBM model

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Theoretical & Applied Mechanics Letters 2024年第3期14卷 157-161页

作者： Pengxuan Luo Jingxin Zhang Yongyong Cao Shaohong Song School of Naval Architecture Ocean&Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China MOE Key Laboratory of Hydrodynamics Shanghai Jiao Tong UniversityShanghai 200240China Shanghai city Tou waterway construction Co. LTDShanghai 200092China

A numerical study of linear wave scattering over a floating platform has been simulated by an efficient numericalmodel in this *** non-hydrostatic model is used to simulate the free surface and the uneven *** thesolid body modelling,the immersed boundary method(IBM)is implemented by introducing a virtual boundaryforce into the momentum equations to emulate the boundary *** implementation enhances theability of the model to simulate interactions between waves and floating structures.A numerical case involvingwave interactions with a floating platform is studied to validate the numerical *** simulating the wavepropagation,the numerical model captures the variation of the wave scattering very well,which verifies theperformance of the numerical model and the robust strategy of the IBM.

关键词： Non-hydrostatic model Immersed boundary method Wave structure interaction Floating platform

Contributors to tidal duration asymmetry with varied coastline configurations on western shelf of Yellow Sea

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Water Science and Engineering 2024年第1期17卷 1-12页

作者： Xi Feng Zheng Li Hui Feng Jia-yan Yang Shou-peng Xie Wei-bing Feng College of Harbor.Coastal and Offshore Engineering Hohai UniversityNanjing 210098China China Harbour Engineering Co. LtdBeijing 100027China Key Laboratory of Port Waterway and Sedimentation Engineering of the Ministry of CommunicationsNanjing 210029China China South-to-North Water Diversion Corporation Limited Beijing 100036China

Coastal management in China is confronted with an urgent choice between natural restoration and maintenance of existing seawalls and reclaimed land for economic development.A key criterion for making this decision is the resilience to coastal flooding,which depends on the ability to predict tidal *** duration asymmetry(TDA)is a key parameter in determination of the arrival and duration of flood *** study selected the western inner shelf of the Yellow Sea(WYS)as the study area and investigated the responses of TDA to different shoreline configurations and relative sea level *** responses of TDA to shoreline reconstruction yielded spatial variability locally and *** the nearshore area,the responses of TDA to the complex ocean environment mainly originated from the combined functions of reflection,bottom friction,and advection,which controlled the energy transfer from M2 or S2 constituents to their overtides or compound *** sensitivity of TDA to coastline typologies was not limited to coastal waters but could stretch over the entire inner *** vulnerability of tidal responses was due to the displacement of the M2 amphidrome of the Kelvin wave on the WYS,which in turn changed tidal energy fluxes over the *** relative sea level rise could intensify the feedback of TDA to seawalls and land reclamation.

关键词： Tidal duration asymmetry Western inner shelf of Yellow Sea Natural restoration Relative sea level rise Tidal amphidrome

Joint Communication-Caching-Computing Resource Allocation for Bidirectional Data Computation in IRS-Assisted Hybrid UAV-Terrestrial Network

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Chinese Journal of Electronics 2024年第4期33卷 1093-1103页

作者： Yangzhe LIAO Lin LIU Yuanyan SONG Ning XU School of Information Engineering Wuhan University of Technology

Joint communication-caching-computing resource allocation in wireless inland waterway communications enables resource-constrained unmanned surface vehicles(USVs) to provision computation-intensive and latencysensitive tasks forward beyond fifth-generation(B5G) and sixth-generation(6G) era. The power of such resource allocation cannot be fully studied unless bidirectional data computation is properly managed. A novel intelligent reflecting surface(IRS)-assisted hybrid UAV-terrestrial network architecture is proposed with bidirectional tasks. The sum of uplink and downlink bandwidth minimization problem is formulated by jointly considering link quality, task execution mode selection, UAVs trajectory, and task execution latency constraints. A heuristic algorithm is proposed to solve the formulated challenging problem. We divide the original challenging problem into two subproblems, i.e., the joint optimization problem of USVs offloading decision, caching decision and task execution mode selection, and the joint optimization problem of UAVs trajectory and IRS phase shift-vector design. The Karush–Kuhn–Tucker conditions are utilized to solve the first subproblem and the enhanced differential evolution algorithm is proposed to solve the latter one. The results show that the proposed solution can significantly decrease bandwidth consumption in comparison with the selected advanced algorithms. The results also prove that the sum of bandwidth can be remarkably decreased by implementing a higher number of IRS elements.

关键词： Wireless communication Heuristic algorithms Bandwidth Network architecture Downlink Trajectory Resource management

Arc additive manufacturing of gradient hot forging die with shaped waterways

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China Welding 2024年第1期33卷 27-39页

作者：余圣甫林海涛邱源 State Key Laboratory of Materials Processing and Die&Mould technology Huazhong University of Science and TechnologyWuhan 430074China

Under the working environment of high temperature and strong load impact,hot forging die is prone to failure which reduces the service life of *** arc additive manufacturing in the die cavity,a gradient material hot forging die with high precision,superior per-formance,and conformal cooling channels is *** 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 *** kinds of gradient flux-cored wires are designed for the surface of 5CrNiMo steel,and the microstructure and mechanical properties between gradient interfaces were *** 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 *** 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 *** 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 *** 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.

关键词： gradient materials shaped waterways arc additive manufacturing mechanical property

Co_(3)O_(4)-ZnO/rGO catalyst preparation and rhodamine B degradation by sulfate radical photocatalysis

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浙江大学学报(英文版)A辑:应用物理与工程 2023年第8期24卷 710-721页

作者： Zhanmei ZHANG Yi ZHANG Xilin CHEN Ziran HUANG Zuqin ZOU Huaili ZHENG Key Laboratory of Hydraulic and waterway Engineering of the Ministry of Education School of River and Ocean EngineeringChongqing Jiaotong UniversityChongqing 400074China National Engineering Research Center for Inland waterway Regulation Chongqing 400074China College of Environment and Ecology Chongqing UniversityChongqing 400044China

The development of a combined photocatalytic system with peroxymonosulfate (PMS) has great potential applications in the degradation and treatment of aqueous organic pollutants. Herein, a Co_(3)O_(4)-ZnO/rGO was prepared by a hydrothermal method using cobalt acetate, zinc acetate, and reduced graphene oxide (rGO) as the main raw materials. The physical and chemical characteristics of the obtained catalyst were analyzed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS),scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR). The photocatalytic features and capacities of the catalytic materials to activate PMS were investigated. Co_(3)O_(4)-ZnO/rGO exhibited stronger photocatalytic activity and ability to activate PMS than Co_(3)O_(4)/rGO or ZnO/rGO, and significantly improved the ability of PMS and photocatalysis to synergistically degrade rhodamine B (RhB), with a degradation rate of 90.40% within 40 min. The mechanism of RhB degradation was proposed based on characterization of materials, evaluation of RhB degradation efficiency, and analysis of the active species involved. The unique particle/sheet structure of Co_(3)O_(4)-ZnO/rGO provides a large number of active sites, and the formation of heterojunctions between Co_(3)O_(4) and ZnO improves carrier separation and transport in the reaction system. Our study offers a reference for designing more effective heterojunction catalysts based on the combination of PMS and photocatalytic technology.

关键词： Co_(3)O_(4)-ZnO/rGO catalyst Rhodamine B(RhB) Heterojunction Photocatalysis Peroxymonosulfate(PMS)

An ERA5 tropospheric parameters-augmented approach for improving GNSS precise point positioning

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Geodesy and Geodynamics 2023年第5期14卷 467-476页

作者： Liangke Huang Feifan Liu Lijie Guo Guiwen Lan Lv Zhou Cheng Wang Lilong Liu College of Geomatics and Geoinformation Guilin University of TechnologyGuilin 541006China Wuhan Changjiang waterway Rescue and Salvage Bure Wuhan 430014China Guangxi Institute of Natural Resources Survey and Monitoring Nanning530023China

Precise Point Positioning(PPP) technology has developed into a potent instrument for geodetic positioning, ionospheric modeling, tropospheric atmospheric parameter detection, and seismic *** atmospheric reanalysis data products’ accuracy and spatiotemporal resolution have improved recently, it has become important to apply these products to obtain high-accuracy tropospheric delay parameters, like zenith tropospheric delay(ZTD) and tropospheric horizontal gradient. These tropospheric delay parameters can be applied to PPP to reduce the convergence time and to increase the accuracy in the vertical direction of the position. The European Centre for Medium-Range Weather Forecasts Reanalysis 5(ERA5) atmospheric reanalysis data is the latest product with a high spatiotemporal resolution released by the European Center for Medium-Range Weather Forecasts(ECMWF). Only a few researches have evaluated the application of ERA5 data to Global Navigation Satellite System(GNSS)PPP. Therefore, this study compared and validated the ZTD products derived from ERA5 data using ZTD values provided by 290 global International GNSS Service(IGS) stations for 2016-2017. The results indicated a stable performance for ZTD, with annual average bias and RMS values of 0.23 cm and 1.09 cm,respectively. Further, GNSS observations for one week in each of the four seasons(spring: DOY 92-98;summer: DOY 199-205;autumn: DOY 275-281;and winter: DOY 22-28) from 34 multi-GNSS experiments(MGEX) stations distributed globally in 2016 were considered to evaluate the performance of ERA5-derived tropospheric delay products in GNSS PPP. The performance of ERA5-enhanced PPP was compared with that of the two standard GNSS PPP schemes(without estimated tropospheric horizontal gradient and with estimated tropospheric horizontal gradient). The results demonstrated that ERA5-enhanced GNSS PPP showed no significant improvement in the convergence times in both the Eastern(E) and Northern(N) directions, while the

关键词： Precise point positioning ERA5 atmospheric reanalysis data Multi-GNSS Tropospheric delay

Mechanism of the Impact of Floods and Typhoons on the Morphological Evolution of the Yangtze Estuary

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China Ocean Engineering 2023年第3期37卷 447-457页

作者： JIAO Jian DING Lei HAN Yu-fang SUN Jie-ying YANG Xiao-yu HUANG Yu-ming DOU Xi-ping Key Laboratory of Port Waterway and Sedimentation Engineering of MOTNanjing Hydraulic Research InstituteNanjing 210029China State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan 430072China

In the last two decades,the Yangtze Estuary has undergone significant changes under the influence of reduced sediment inflow and estuary *** study investigates the influence of floods and typhoons on sediment concentration and the morphological evolution of shoals and channels in the Yangtze *** analysis is conducted through the utilization of topographic data measured pre-and post-flood events and observations of hydro-sedimentary changes during *** using a generalized estuary mathematical model,this study examines the interplay between varying tidal ranges,tidal divisions,runoff volumes,and regulation projects on the erosion and deposition of shoals and channels in bifurcated *** results show that due to the implementation of river and waterway regulation projects,the impact of the 2020 flood on the main channel and shoal was significantly less than that of the1998 *** swing amplitude of the South Branch main channel ***,local river sections such as the Southern waterway of Baimao Shoal exhibited *** typhoons,sediment concentration in the 20 cm above the bottom increased significantly and was closely related to wave processes,with a weakened correlation to tidal *** typhoons,high shoals in South Passage above 0 m were silted up,while the terrain on one side of the tail of Jiuduan Shoal in the downstream deep-water area was generally scoured due to strong wave *** generalized mathematical model of the bifurcated estuary revealed that M2 tidal component contributed most to the ero sion and deposition evolution of estuary shoals and channels,with floods exhibiting characteristics of sedime ntation on shoals and erosion on *** the implementation of a branch rectification project,branch resistance increased,diversion decreased,and the riverbed changed from pre-project erosion to post-project sedimentation,with an increase in erosion in non-project branches.

关键词： the Yangtze Estuary flood typhoon morphological evolution

Stormwater Quality Characteristics and Reuse Analysis of Different Underlying Surfaces at Wanzhou North Station

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Journal of Environmental & Earth Sciences 2022年第2期4卷 45-53页

作者： Shaochun Yuan Ting Li Qingwei Yang Shun You Tao He Bo Lv Key Laboratory of Hydraulic and waterway Engineering of the Ministry of Education Chongqing Jiaotong UniversityChongqing400074China Chongqing Engineering technology Research Center for Sponge City Construction Chongqing400020China Chongqing Academy of Science and technology Chongqing401123China

In response to the water shortage in Wanzhou North Station(WNS),the authors investigated the stormwater quality characteristics with different underlying surfaces of WNS and carried out stormwater reuse analysis in conjunction with the InfoWorks ICM *** results show that during heavy,torrential,and moderate rainfall,the road stormwater runoff has the highest concentrations of pollutants,with an average EMC(event mean concentration)value of 206 mg/L for *** the square runoff,the average EMC values of COD,SS,TN,and TP are 108 mg/L,395 mg/L,2.113 mg/L,and 0.128 mg/L,in comparison,the average EMC values of the corresponding indexes for the roof runoff are 65 mg/L,212 mg/L,1.449 mg/L,and 0.086 mg/L,respectively,demonstrating their potential for *** R2(coefficient of determination)of SS and COD in both roof and square runoff are greater than 0.85,with a good correlation,indicating that SS removal is the key to stormwater *** ICM analysis shows that the recyclable volume of rainwater from WNS in 2018 is 29,410 m3,accounting for 61.8%of the total annual *** study is expected to provide an ideal reference for the stormwater management of public buildings in mountainous areas.

关键词： Stormwater quality Underlying surface Recyclable rainfall Stormwater utilization

Soil-water characteristic surface model of soil-rock mixture

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Journal of Mountain Science 2023年第9期20卷 2756-2768页

作者： WANG Kui HUI Ying ZHOU Chuan LI Xue RONG Yao Institute of Engineering Research Centre of Diagnosis technology of Hydro-Construction Chongqing Jiaotong UniversityChongqing 400074China Changjiang Fuling waterway Division Chongqing 408000China Institute of Jiangxi Transportation Institute Co. LtdNO.809 Jinsha AveXiaolan Economic Development ZoneNanchang 330200China

The relationship between the water content or saturation of unsaturated soils and its matrix suction is commonly described by the soilwater characteristic curve(SWCC).Currently,study on the SWCC model is focused on fine-grained soils like clay and silty soils,but the SWCC model for grinding soil-rock mixture(SRM)is less *** that the SRM is in a certain compaction state in the actual project,this study established a surface model with three variables of coupling compaction degree-substrate suction-moisture content based on the Cavalcante-Zornberg soil-water characteristic curve ***,the influence of each fitting parameter on the curve was *** the common SRM,the soil-water characteristic test was ***,the experimental measurements exhibit remarkable consistency with the mode *** analysis shows that the surface model intuitively describes the soil-water characteristics of grinding SRM,which can provide the SWCC of soils with bimodal pore characteristics under specific compaction ***,it can reflect the influence of compaction degrees on the SWCC of rock-soil mass and has a certain prediction *** SWCC of SRM with various soil-rock ratios have a double-step *** the increase in compaction degree,the curves as a whole tend toward decreasing mass moisture *** curve changes are mainly concentrated in the large pore section.

关键词： Soil-rock mixture Soil-water characteristic Surface model Compaction effect