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Assessment of Storm Surge and Flood Inundation in Chittagong City of Bangladesh Based on ADCIRC and GIS

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Journal of Ocean University of China 2023年第6期22卷 1473-1486页

作者： LIU Yuxin LI Songtao wang zhifeng National Ocean Technology Center Tianjin 300110China Shandong Provincial Key Laboratory of Ocean Engineering&College of Engineering Ocean University of ChinaQingdao 266100China

Coastal flooding caused by tropical cyclones has long been a major threat to life,property,and infrastructure in coastal *** study assessed the risk of flooding in Chittagong,southeastern Bangladesh,under extreme sea level scenarios caused by high astronomical tides and storm *** Jelesnianski typhoon model and the ADvanced CIRCulation hydrodynamic model were used to simulate 91 typhoons that occurred in the Bay of Bengal between 1981 and 2017,and observational data were used for model *** inundation model was based on a digital elevation model and a seed spread algorithm,and a geographical information system was used to visualize the flood *** four scenarios,the changes in flood levels caused by sea level rise had no signifi-cant influence on the extent of flooding in *** flood levels of 8.82m(50-year storm surge without sea level rise)and 8.89 m(50-year storm surge with sea level rise),the maximum estimated area of inundation was 11.35 km^(2).The western coastal and southeastern river coastal plain areas of Chittagong have the highest risk of inundation due to their low-lying *** flood levels of 9.83m(100-year storm surge without sea level rise)and 9.97m(100-year storm surge with sea level rise),the maximum simulated flood extent was 36.44km^(2).Simulated floodwaters propagated in a south–north direction,and most of the northern areas of the city are at risk of inundation under these scenarios.

关键词： typhoon storm surge extreme sea level inundation

Intensity of Level Ice Simulated with the CICE Model for Oil-Gas Exploitation in the Southern Kara Sea, Arctic

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Journal of Ocean University of China 2022年第5期21卷 1099-1108页

作者： DUAN Chenglin wang zhifeng DONG Sheng College of Engineering Ocean University of ChinaQingdao 266100China

Sea ice is the predominant natural threat to marine structures and oil-gas exploitation in the ***,for ice-resistant structural design,long-term successive level ice thickness measurements are still *** fill this gap in the southern Kara Sea,the Los Alamos Sea Ice Model(CICE)is applied to achieve better simulation at the local and regional *** on the validation against ice thickness observations in March and April in 1980-1986,the statistical root-mean-square error is determined to be less than 0.2 ***,based on the hindcast data,the spatiotemporal distributions of level ice thickness are analyzed annually,seasonally,and monthly,with thicker level ice of 1.2-1.5 m in spring and large ice-free zones in September and *** floating platforms,a novel ice grade criterion with five classifications,namely,excellent,good,moderate,severe,and catastrophic,is *** first two grades are most suitable for offshore activities,particularly from August to October,and the moderate grade is acceptable if with ice-resistant ***,hostile ice conditions are discussed in terms of the generalized extreme value *** statistics reveal that at a return period of 100 yr,extreme level ice is primarily between 0.6 m and 1.0 m in *** present investigation could be a useful reference for a feasibility study of the potential risk analysis and ice-resistant operation of oil-gas exploitation in the Arctic.

关键词： level ice CICE spatiotemporal distribution return period ice-resistant floating platform southern Kara Sea

Thermal performance of a single-layer packed metal pebble-bed exposed to high energy fluxes

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Frontiers in Energy 2021年第2期15卷 513-528页

作者： Shengchun ZHANG zhifeng wang Hui BIAN Pingrui HUANG Key Laboratory of Solar Thermal Energy and Photovoltaic System Chinese Academy of SciencesBeijing 100190China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China Beijing Engineering Research Center of Solar Thermal Power Beijing 100190China 2.Lanzhou University of TechnologyLanzhou 730050China

It is difficult to accurately measure the temperature of the falling particle receiver since thermocouples may directly be exposed to the solar *** study analyzes the thermal performance of a packed bed receiver using large metal spheres to minimize the measurement error of particle temperature with the sphere temperature reaching more than 700°C in experiments in a solar furnace and a solar *** numerical models of a single sphere and multiple spheres are verified by the *** multiple spheres model includes calculations of the external incidence,view factors,and heat *** effects of parameters on the temperature variations of the spheres,the transient thermal efficiency,and the temperature uniformity are investigated,such as the ambient temperature,particle thermal conductivity,energy flux,sphere diameter,and sphere *** the convection is not considered,the results show that the sphere emissivity has a significant influence on the transient thermal efficiency and that the temperature uniformity is strongly affected by the energy flux,sphere diameter,and sphere *** the emissivity increases from 0.5 to 0.9,the transient thermal efficiency and the average temperature variance increase from 53.5%to 75.7%and from 14.3%to 27.1%at 3.9 min,*** average temperature variance decreases from 29.7%to 9.3%at 2.2 min with the sphere diameter increasing from 28.57 mm to 50 *** the dimensionless energy flux increases from 0.8 to 1.2,the average temperature variance increases from 13.4%to 26.6%at 3.4 min.

关键词： packed bed solar thermal power plants high heat fluxes radiative heat transfer

Dynamic Simulation of a Novel Solar Polygeneration System for Heat, Power and Fresh Water Production based on Solar Thermal Power Tower Plant

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Journal of Thermal Science 2020年第2期29卷 378-392页

作者： LI Xing wang zhifeng YANG Ming YUAN Guofeng Key Laboratory of Solar Thermal Energy and Photovoltaic System Chinese Academy of SciencesBeijing 100190China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Beijing Engineering Research Center of Solar Thermal Power Beijing 100190China

A novel solar polygeneration system for heat, power and fresh water production with absorption heat pump(AHP) and humidification-dehumidification(HDH) desalination system was proposed for high-efficiency utilization of solar energy. A case study of the proposed system was investigated based on 1 MW solar thermal power(STP) tower plant located in Beijing. Depending on mathematical modeling of the proposed system, corresponding modules were developed in TRNSYS. Meanwhile, control and operation strategies were fully studied with principal of solar energy cascade utilization. The thermodynamic performance of the proposed system was dynamically simulated at one minute intervals in a typical day. It was found that solar energy utilization level was improved with the help of solar thermal storage system and continuous heating in different operation modes met well with flexible heating loads from 93.76 kW to 169.49 kW. During AHP operation period, its Coefficient of Performance(COP) varied from 1.39 to 1.73 due to recoverable condensate heat restricted by heating demand. Meanwhile, fresh water production of HDH increased from 352.05 kg/h to 416.62 kg/h with Gained Output Ratio(GOR) increase from 2.48 to 2.67. Compared with original STP tower plant, maximum power generation efficiency was increased from 18.66% to 19.22% with power from 1169.69 kW to 1204.44 kW.

关键词： polygeneration solar thermal power dynamic simulation absorption heat pump humidification-dehumidification

Experimental Study on Melting Process in an Industrial Level Molten Salt Tank

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Journal of Thermal Science 2020年第2期29卷 457-463页

作者： LI Zhi ZHANG Qiangqiang wang zhifeng LI Jun Key Laboratory of Solar Thermal Energy and Photovoltaic System of Chinese Academy of Sciences Beijing 100190China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Beijing Engineering Research Center of Solar Thermal Power Beijing 100190China

Thermal energy storage(TES) is an important part of concentrating solar power(CSP) plants. The primary advantage of TES in CSP plants is the ability to dispatch electrical output to match peak demand periods and reduce the levelized cost of electricity. The major challenge of the molten salt is its high freezing point, leading to additional complicating freeze protection. This paper presents the experimental results of melting process of a mixed nitrate salt with a melting temperature of 115℃ in a 20 m^3 industrial level tank. Twenty electrical heaters inside the tank are used to heat the salt with a total maximum input power of 240 kW. In order to ensure a safe and fast melting process, the whole process adopted an operating strategy of combining automatic control with manual control. The whole melting process lasted for 314 hours. The salt temperature showed the greatest increase in the first 38 hours. Finally, an economic operation mode of molten salt heat storage tank was obtained.

关键词： molten salt melting concentrating solar power thermal energy storage

Investigation of mechanical performance of prestressed steel arch in tunnel

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Frontiers of Structural and Civil Engineering 2017年第3期11卷 360-367页

作者： Yaqiong wang Yunxiao XIN Yongli XIE Jie LI zhifeng wang a School of Highway Shaanxi Provincial Major Laboratory for Highway Bridge & Tunnel Chang'an University Xi'an 710064 China Shaanxi Communication Technology Consulting Co. Ltd. Xi'an 710068 China

In the traditional tunneling method, the steel arch are often adopted to support surrounding rock to ensure the structural stability. If the steel arch is prestressed in time, tunnel support can effectively prevent the development of rock crack, thereby increasing the overall strength of tunnel support and suppress the deformation of the surrounding rock. Based on the mechanical model of steel arch established in this paper, the stress distribution of steel arch is investigated via the numerical simulation method, and the impact on surrounding rock is also analyzed. Through a field test, the rules of the arch strain distribution are observed and discussed. The results show that the prestressed steel arch structure can provide effective support and the stress gradually decreases from stress point to another arch springing. Furthermore, the stress distribution applied by the prestressed steel arch on the surrounding rock is uniform in a certain extent, and it is suggested that this construction method utilizing the prestressed steel arch to squeeze surrounding rock is feasible from a theoretical view.

关键词： tunnel support prestressing force steel arch numerical analysis

Experiment study of a quartz tube falling particle receiver

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Frontiers in Energy 2017年第4期11卷 472-479页

作者： Tianjian wang Fengwu BAI Shunzhou CHU Xiliang ZHANG zhifeng wang Institute of Electrical Engineering Chinese Academy of Sciences Beijing 100190 China Key Laboratory of Solar Thermal Energy and Photovoltaic System Chinese Academy of Sciences Beijing 100190 China Beijing Engineering Research Center of Solar Thermal Power Beijing 101107 China University of Chinese Academy of Sciences Beijing 100190 China

This paper presents an experimental evaluation of a specially designed falling particle receiver. A quartz tube was used in the design, with which the particles would not be blown away by wind. Concentrated solar radiation was absorbed and converted into thermal energy by the solid particles flowed inside the quartz tube. Several experiments were conducted to test the dynamic thermal performance of the receiver on solar furnace system. During the experiments, the maximum particle temperature rise is 212~C, with an efficiency of 61.2%, which shows a good thermal performance with a falling distance of 0.2 m in a small scale particle receiver. The average outlet particle temperature is affected by direct normal irradiance （DNI） and other factors such as wind speed. The solid particles obtain a larger viscosity with a higher temperature while smaller solid particles are easier to get stuck in the helix quartz tube. The heat capacity of the silicon carbide gets larger with the rise of particle temperature, because as the temperature of solid particles increases, the temperature rise of the silicon carbide decreases.

关键词： solar thermal electricity central receiver,particle receiver experimental research

Comparison of Bottom-up Filling in Electroless Plating with an Addition of PEG, PPG and EPE

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Chinese Journal of Chemistry 2011年第3期29卷 422-426页

作者： Yang, zhifeng wang, Zhixiang wang, Xu wang, Zenglin Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education and School of Chemistry and Materials Science Shaanxi Normal University Xi'an Shaanxi 710062 China

The bottom-up filling capabilities of electroless copper plating bath with an addition of additives, such as poly- ethylene glycol （PEG）, polypropylene glycol （PPG） and triblock copolymers of PEG and PPG with ethylene oxide terminal blocks termed EPE, were investigated by the cross-sectional scanning electron microscopy （SEM） obser- vation of sub-micrometer trenches. Though three additives had inhibition for electroless copper deposition, the suppression degrees of three additives were different. EPE-2000 had the strongest suppression for electroless copper deposition, and the suppression of PEG-2000 was the weakest. The bottom-up filling capability of electroless copper was investigated in a plating bath containing different additives with the concentration of 2.0 mg/L. The cross-sectional SEM observation indicated the trenches with the width of 280 nm and the depth of 475 nm were all completely filled by the plating bath with an addition of EPE-2000, but the trenches were not completely filled by the plating bath with an addition of PEG-2000 or PPG-2000, and some voids appeared. Linear sweep voltammetry measurement indicated that three additives all inhibited the cathodic reduction reaction and the anodic oxidation reaction, and the inhibition of EPE-2000 was the strongest among three additives, which agreed with that of the deposition rate of electroless copper. Significant differences in surface roughness of deposited copper film were observed by UV-visible near-infrared for different suppressors, and the bright and smooth of deposited copper film were in accordance with the inhibition of three additives.

关键词： bottom-up fill electroless plating damascene copper additives triblock copolymer

The low-frequency variance of the ocean surface wave field in the area of the Antarctic Circumpolar Current

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Acta Oceanologica Sinica 2013年第5期32卷 15-21页

作者： ZHANG Xiaoshuang WU Kejian wang Bin wang zhifeng Ocean University of China Key Laboratory of Marine Environmental Information Technology National Marine Data and Information ServiceState Oceanic Administration Physical Oceanography Laboratory Ocean University of China

The low-frequency variance of the surface wave in the area of the Antarctic Circumpolar Current （ACC） and its correlation with the antarctic circumpolar wave （ACW） are focused on. The analysis of the series of 44 a significant wave height （SWH） interannual anomalies reveals that the SWH anomalies have a strong periodicity of about 4-5 a and this signal propagates eastward obviously from 1985 to 1995, which needs about 8 a to complete a mimacircle around the earth. The method of empirical orthogonal function （EOF） is used to analyze the filtered monthly SWH anomalies to study the spatio-temporal distributions and the propagation characteristics of the low-frequency signals in the wave field. Both the dominant wavenumber- 2 pattern in space and the propagation feature in the south Pacific, the south Atlantic and the south Indian ocean show strong consistency with the ACW. So it is reasonable to conclude that the ACW signal also exists in the wave field. The ACW is important for the climate in the Southern Ocean, so it is worth to pay more attention to the large- scale effect of the surface wave, which may also be important for climate studies.

关键词： significant wave height antarctic circumpolar wave empirical orthogonal function low-frequ-ency variance