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Study on Adjoint-Based Optimization Method For Multi-Stage Turbomachinery

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Journal of Thermal Science 2011年第5期20卷 398-405页

作者： weiwei Li Yong Tian Weilin Yi Lucheng Ji weiwei shao Yunhan Xiao School of Aerospace Engineering Beijing Institute of Technology Beijing 100081 China Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100190 China Graduate School of Chinese Academy of Sciences Beijing 100190 China

Adjoint-based optimization method is a hotspot in ***,this paper presents principles of adjoint method from Lagrange multiplier ***,combining a continuous route with thin layer RANS equations,we formulate adjoint equations and anti-physical boundary *** to the multi-stage environment in turbomachinery,an adjoint interrow mixing method is *** techniques of solving flow equations and adjoint equations are almost the same,and once they are converged respectively,the gradients of an objective function to design variables can be calculated using complex method ***,integrating a shape perturbation parameterization and a simple steepest descent method,a frame of adjoint-based aerodynamic shape optimization for multi-stage turbomachinery is *** last,an inverse design of an annular cascade is employed to validate the above approach,and adjoint field of an Aachen 1.5 stage turbine demonstrates the conservation and areflexia of the adjoint interrow mixing *** a direct redesign of a 1+1 counter-rotating turbine aiming to increase efficiency and apply constraints to mass flow rate and pressure ratio is taken.

关键词： adjoint method aerodynamic shape optimization multi-stage turbomachinery N-S equations

A new strategy for integrated urban water management in China：Sponge city

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Science China(Technological Sciences) 2018年第3期61卷 317-329页

作者： WANG Hao MEI Chao LIU JiaHong shao weiwei China Institute of Water Resources and Hydropower Research State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin Beijing 100038 China School of Transportation and Civil Engineering & Architecture Foshan University Guangdong 528000 China Engineering and Technology Research Center for Water Resources and hydroecology of the Ministry of Water Resources Beijing 100044 China

Urban water-related problems associated with rapid urbanization, including waterlogging, water pollution, the ecological degradation of water, and water shortages, have caused global concerns in recent years. In 2013, in order to mitigate increasingly severe urban water-related problems, China set forth a new strategy for integrated urban water management(IUWM) called the "Sponge City". This is the first holistic IUWM strategy implemented in a developing country that is still undergoing rapid urbanization, and holds promise for application in other developing countries. This paper aims to comprehensively summarize the sponge city. First, this paper reviews prior studies and policies on urban water management in China as important background for the sponge city proposal. Then, the connotations, goals, and features of the sponge city are summarized and ***, the challenges, research needs, and development directions pertinent to the sponge city are discussed based on investigations and studies conducted by the authors. The sponge city in China has a short history—given this, there are many issues that should be examined with regard to the stepwise implementation of the Sponge City Programme(SCP). Accordingly, the authors perceive this study as only the beginning of abundant studies on the sponge city.

关键词： flexible adaptation urban hydrological cycle low impact development green infrastructure

Analysis of driving forces of water demand in Jing-Jin-Ji district in recent years based on water demand field theory

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Science China(Technological Sciences) 2020年第12期63卷 2593-2605页

作者： HUANG Ze LIU JiaHong MEI Chao WANG Hao shao weiwei LI ZeJin College of New Energy and Environment Jilin UniversityChangchun 130021China State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing 100038China School of Transportation and Civil Engineering&Architecture Foshan UniversityFoshan 528000China

In recent years,urbanization has accelerated and the gap between urban water supply and demand has become more *** phenomenon has led to greater demands on urban water resource management. Thus,analyses of the forces that drive urban water demand growth can help efficient management of urban water resources. "Jing-Jin-Ji" refers to the district composed of Beijing and Tianjin,municipality as well as Hebei Province,which is among the political and economic centers of China. The traditional analysis of driving force for water resources often consider cities as independent individuals and ignores the interaction between them. Such method cannot describe the spatial distribution of regional water demand. In this study,the water demand field theory is used to construct water demand and social development fields for the Jing-Jin-Ji district with relevant indicators. The distribution trends of the two fields,and the correlation of their intensities,are then analyzed. Principal component analysis is used to specifically determine the forces that drive water demand at different stages of *** indicate that the water demand field theory can accurately describe spatial variations in water demand intensity in the study area. The main driving force for water demand in the Jing-Jin-Ji district from 2000 to 2014 is the growth of urban population. However,in 2015 and 2016,"GDP of the tertiary industry" overtook it. The results of this study can serve as a basis for regional water demand forecasting,with large potential to be applied to urban water resource management.

关键词： water demand field degree of social development driving forces of water demand

Combustion of Hydrogen in an Experimental Trapped Vortex Combustor

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Journal of Thermal Science 2009年第3期18卷 256-261页

作者： Hui Wu Qin Chen weiwei shao Yongliang Zhang Yue Wang Yunhan Xiao Graduate University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Advanced Energy and Power IET CAS Beijing 100190 China

Combustion performances of pure hydrogen in an experimental trapped vortex combustor have been tested underdifferent operating conditions. Pressure fluctuations, NOx emissions, OH distributions, and LBO (Lean Blow Out)were measured in the tests. Results indicate that the TVC test rig has successfully realized a double vortex constructionin the cavity zone in a wide range of flow conditions. Hydrogen combustion in the test rig has achievedan excellent LBO performance and relatively low NOx emissions. Through comparison of dynamic pressure data,OH fluctuation images, and NOx emissions, the optimal operating condition has been found out to be Φp=0.4,fuel split=0.4, and primary air/fuel premixed.

关键词： trapped vortex combustor hydrogen combustion

MILD Combustion for Hydrogen and Syngas at Elevated Pressures

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Journal of Thermal Science 2014年第1期23卷 96-102页

作者： HUANG Mingming ZHANG Zhedian shao weiwei XIONG Yan LEI Fulin XIAO Yunhan Key Laboratory of Advanced Energy and Power Institute of Engineering ThermophysicsChinese Academy of Sciences Research Center for Clean Energy and Power Chinese Academy of Sciences

As gas recirculation constitutes a fundamental condition for the realization of MILD combustion, it is necessary to determine gas recirculation ratio before designing MILD combustor. MILD combustion model with gas recirculation was used in this simulation work to evaluate the effect of fuel type and pressure on threshold gas recirculation ratio of MILD mode. Ignition delay time is also an important design parameter for gas turbine combustor, this parameter is kinetically studied to analyze the effect of pressure on MILD mixture ignition. Threshold gas recirculation ratio of hydrogen MILD combustion changes slightly and is nearly equal to that of 10 MJ/Nm3syngas in the pressure range of 1-19 atm, under the conditions of 298 K fresh reactant temperature and 1373 K exhaust gas temperature, indicating that MILD regime is fuel flexible. Ignition delay calculation results show that pressure has a negative effect on ignition delay time of 10 MJ/Nm3syngas MILD mixture, because OH mole fraction in MILD mixture drops down as pressure increases, resulting in the delay of the oxidation process.

关键词： MILD combustion Gas turbine combustor Syngas Gas recirculation ratio Ignition delay time

The Influence of Fuel-Air Swirl Intensity on Flame Structures of Syngas Swirl-Stabilized Diffusion Flame

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Journal of Thermal Science 2010年第3期19卷 276-283页

作者： weiwei shao Yan Xiong Kejin Mu Zhedian Zhang Yue Wang Yunhan Xiao Research Center for Energy and Power Chinese Academy of Sciences Beijing China Key Laboratory of Advanced Energy and Power Chinese Academy of Sciences (Institute of Engineenng Thermophysics) Beijing China P.O. Box 2706 Beijing 100190 China Nanjing TianLing Energy Tech. Co Ltd Jiangsu 210018 China

Flame structures of a syngas swirl-stabilized diffusion flame in a model combustor were measured using the OH-PLIF method under different fuel and air swirl *** flame operated under atmospheric pressure with air and a typical low heating-value syngas with a composition of 28.5% CO,22.5% H2 and 49% N2 at a thermal power of 34 *** indicate that increasing the air swirl intensity with the same fuel,swirl intensity flame structures showed little difference except a small reduction of flame length;but also,with the same air swirl intensity,fuel swirl intensity showed great influence on flame shape,length and reaction zone ***,compared with air swirl intensity,fuel swirl intensity appeared a key effect on the flame structure for the model *** OH-PLIF images showed that three distinct typical structures with an obvious difference of reaction zone distribution were found at low swirl intensity,while a much compacter flame structure with a single,stable and uniform reaction zone distribution was found at large fuel-air swirl *** means that larger swirl intensity leads to efficient,stable combustion of the syngas diffusion flame.

关键词： Diffusion Flame Swirl Intensity Flame Structure OH-PLIF

Urban flood risk assessment under rapid urbanization in Zhengzhou City,China

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Regional Sustainability 2023年第3期4卷 332-348页

作者： LI Guoyi LIU Jiahong shao weiwei State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resource and Hydropower ResearchBeijing100038China Water Resources and Water Ecological Engineering Technology Research Center of Ministry of Water Resources Beijing100044China

With accelerated urbanization and climate change,urban flooding is becoming more and more *** risk assessment is an important task for flood management,so it is crucial to map the spatial and temporal distribution of flood *** paper proposed an urban flood risk assessment method that takes into account the influences of hazard,vulnerability,and exposure,by constructing a multi-index urban flood risk assessment framework based on Geographic Information System(GIS).To determine the weight values of urban flood risk index factors,we used the analytic hierarchy process(AHP).Also,we plotted the temporal and spatial distribution maps of flood risk in Zhengzhou City in 2000,2005,2010,2015,and *** analysis results showed that,the proportion of very high and high flood risk zone in Zhengzhou City was 1.362%,5.270%,4.936%,12.151%,and 24.236%in 2000,2005,2010,2015,and 2020,*** is observed that the area of high flood risk zones in Zhengzhou City showed a trend of increasing and expanding,of which Dengfeng City,Xinzheng City,Xinmi City,and Zhongmu County had the fastest growth rate and the most obvious *** flood risk of Zhengzhou City has been expanding with the development of *** method is adapted to Zhengzhou City and will have good adaptability in other research areas,and its risk assessment results can provide a scientific reference for urban flood management *** the future,the accuracy of flood risk assessment can be further improved by promoting the accuracy of basic data and reasonably determining the weight values of index *** risk zoning map can better reflect the risk distribution and provide a scientific basis for early warning of flood prevention and drainage.

关键词： Urban flood Flood risk assessment Geographic Information System(GIS) Multi-index system method Urbanization Zhengzhou City

Density But Not Kinship Regulates the Growth and Developmental Traits of Chinese Tiger Frog (Hoplobatrachus chinensis) Tadpoles

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Asian Herpetological Research 2014年第2期5卷 113-118页

作者： Li WEI weiwei shao Guohua DING Xiaoli FAN Zhihua LIN College of Ecology Lishui University

Kinship and density are believed to affect important ecological processes such as intraspecific competition, predation, growth, development, cannibalism, habitat selection and mate choice, In this work, we used Chinese tiger frog Hoplobatrachus chinensis tadpoles as an experimental model to investigate the effects of kinship and density on growth and development of this species over a 73 day period. The results showed that density can affect the growth and developmental traits （survival rate, larval period, size at the limb bud protrusion/metamorphic climax and body mass at different life stages） of H. chinensis tadpoles, while kinship does not. Tadpoles took longer to develop and potential metamorphosis was greater in high density groups of both sibling and non-siblings. The interaction of kinship and density did not significantly influenced growth traits of H. chinensis tadpoles during the experimental period. For coefficient variations of each growth trait, no differences were detected between sibling and non-sibling groups. These findings provide valuable information on the basic ecology of H. chinensis which will be helpful in future studies of other anuran species.

关键词： Kinship density intraspecific competetion growth metamorphic climax Hoplobatrachus chinensis

In-plane heterostructured Ag_(2)S-In_(2)S_(3) atomic layers enabling boosted CO_(2) photoreduction into CH_(4)

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Nano Research 2021年第12期14卷 4520-4527页

作者： weiwei shao Shumin Wang Juncheng Zhu Xiaodong Li Xingchen Jiao Yang Pan Yongfu Sun Yi Xie Hefei National Laboratory for Physical Sciences at Microscale CAS Centre for Excellence in NanoscienceNational Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei230026China Institute of Energy Hefei Comprehensive National Science CenterHefei230031China

Sluggish separation and migration kinetics of the photogenerated carriers account for the low-efficiency of CO_(2) photoreduction into CH_(4). Design and construction two-dimensional (2D) in-plane heterostructures demonstrate to be an appealing approach to address above obstacles. Herein, we fabricate 2D in-plane heterostructured Ag_(2)S-In_(2)S_(3) atomic layers via an ion-exchange strategy. Photoluminescence spectra, time-resolved photoluminescence spectra, and photoelectrochemical measurements firmly affirm the optimized carrier dynamics of the In_(2)S_(3) atomic layers after the introduction of in-plane heterostructure. In-situ Fourier transform infrared spectroscopy spectra and density functional theory (DFT) calculations disclose the in-plane heterostructure contributes to CO_(2) activation and modulates the adsorption strength of CO* intermediates to facilitate the formation of CHO* intermediates, which are further protonated to CH4. In consequence, the in-plane heterostructure achieves the CH_(4) evolution rate of 20 µmol·g^(−1)·h^(−1), about 16.7 times higher than that of the In2S3 atomic layers. In short, this work proves construction of in-plane heterostructures as a promising method for obtaining high-efficiency CO_(2)-to-CH_(4) photoconversion properties.

关键词： in-plane heterostructure atomic layers carrier dynamics selective CO_(2)photoreduction