The wind environment serves as an important indicator of the comfort level of the human settlement environment.A favorable wind environment in courtyards can offer residents a better living and activity environment.Ba...The wind environment serves as an important indicator of the comfort level of the human settlement environment.A favorable wind environment in courtyards can offer residents a better living and activity environment.Based on the Climatic Suitability Evaluating on Human Settlement,this study employs Computational Fluid Dynamics(CFD)simulation analysis to evaluate the wind environment comfort in rural courtyards,and elucidates the interactions between various factors influencing the courtyard wind environment and the courtyard wind environment.It is anticipated that the findings of this study will serve as a valuable reference for the renovation and new construction of rural houses,with a focus on optimizing the wind environment.展开更多
With the increasing global demand for renewable energy,the application of photovoltaic power generation in mountainous areas is gradually increasing.However,the complex wind environment in mountainous areas poses seve...With the increasing global demand for renewable energy,the application of photovoltaic power generation in mountainous areas is gradually increasing.However,the complex wind environment in mountainous areas poses severe challenges to the design and optimization of solar photovoltaic brackets.Traditional design methods are difficult to cope with the changeable wind speed and direction in mountainous areas,resulting in structural instability or material waste.Researchers have identified the key factors affecting wind response through parametric research and dynamic wind response analysis,so as to optimize the brackets design and improve its adaptability and stability in complex wind environments.In this paper,the complexity of wind speed,wind direction and turbulence characteristics in mountainous areas and their influence on brackets design are explored.Through static and dynamic wind load analysis,the geometrical shape and material selection of the bracket are optimized to enhance its wind resistance.The application of multi-objective optimization model and intelligent optimization algorithm provides an effective solution for the design of solar photovoltaic brackets,ensuring their safety and reliability in complex wind environments.展开更多
Disturbance in wind regime and sand erosion deposition balance may lead to burial and eventual vanishing of a site.This study conducted 3D computational fluid dynamics(CFD)simulations to evaluate the effect of a propo...Disturbance in wind regime and sand erosion deposition balance may lead to burial and eventual vanishing of a site.This study conducted 3D computational fluid dynamics(CFD)simulations to evaluate the effect of a proposed city design on the wind environment of the Crescent Spring,a downwind natural heritage site located in Dunhuang,Northwestern China.Satellite terrain data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)Digital Elevation Model(DEM)were used to construct the solid surface model.Steady-state Reynolds Averaged Navier-Stokes equations(RANS)with shear stress transport(SST)k-ωturbulence model were then applied to solve the flow field problems.Land-use changes were modeled implicitly by dividing the underlying surface into different areas and by applying corresponding aerodynamic roughness lengths.Simulations were performed by using cases with different city areas and building heights.Results show that the selected model could capture the surface roughness changes and could adjust wind profile over a large area.Wind profiles varied over the greenfield to the north and over the Gobi land to the east of the spring.Therefore,different wind speed reduction effects were observed from various city construction scenarios.The current city design would lead to about 2 m/s of wind speed reduction at the downwind city edge and about 1 m/s of wind speed reduction at the north of the spring at 35-m height.Reducing the city height in the north greenfield area could efficiently eliminate the negative effects of wind spee.By contrast,restricting the city area worked better in the eastern Gobi area compared with other parts of the study area.Wind speed reduction in areas near the spring could be limited to 0.1 m/s by combining these two abatement strategies.The CFD method could be applied to simulate the wind environment affected by other land-use changes over a large terrain.展开更多
To improve the outdoor environment of rural settlement and reduce the energy consumption of rural houses in winterin cold areas,the seriously bad wind environment should been controlled and considered. This paper appl...To improve the outdoor environment of rural settlement and reduce the energy consumption of rural houses in winterin cold areas,the seriously bad wind environment should been controlled and considered. This paper applies the method of numerical simulation to simulate the wind environment of some typical arrangement of building and courtyard in winter,and concludes the optimal building and courtyard arrangement types and strategies. It aims to provide some technical supports for improving the wind environment of rural settlements in cold regions.展开更多
The wind environment around residential building groups is increasingly concerned,while the dwelling groups as the elementary unit of planning design,its quality of surrounding wind environment will directly affect pe...The wind environment around residential building groups is increasingly concerned,while the dwelling groups as the elementary unit of planning design,its quality of surrounding wind environment will directly affect people's life. This study based on the climatic conditions of severe cold regions,selects four dwellings groups with different openings scale and position as the research objects,and then simulates and analyzes the wind speed distribution characteristics of each pattern. Meanwhile,it extracts the wind speed values of one hundred points of each pattern and applies the coefficient of uniformity method to the ecological evaluation. It has been found that grouping pattern of buildings has a dramatic effect on the resulting airflow behavior. Configurations that contain a T-shaped central space with small opened side can effectively prevent and contain airflow in the site offer. The interactive influence between layout of dwelling groups and wind environment are explored,so as to provide basis for the planning design of dwelling groups.展开更多
Computational fluid dynamics(CFD)has become the main method for the prediction of the properties of the external wind environment in cities and other urban contexts.A review is presented of the existing literature in ...Computational fluid dynamics(CFD)has become the main method for the prediction of the properties of the external wind environment in cities and other urban contexts.A review is presented of the existing literature in terms of boundary conditions,building models,computational domains,computational grids,and turbulence models.Some specific issues,such as the accuracy/computational cost ratio and the exploitation of existing empirical correlations,are also examined.展开更多
It is important to improve residential thermal comfort in the high dense cities,in which wind environment is crucial.Waterside buildings take an advantage of micro-hydrological-climate in summer that should be used to...It is important to improve residential thermal comfort in the high dense cities,in which wind environment is crucial.Waterside buildings take an advantage of micro-hydrological-climate in summer that should be used to enhance residential thermal comfort especially in the subtropical region.In order to propose design approaches according to the outdoor thermal comfort of the waterside residential,a case study of Shenzhen She Kou residential district has been made.It focused on various factors that could have influence on wind environment for improving thermal comfort.Using wind velocity ratio(ΔRi)criterion,factors of building development volume,building direction and layout pattern,open space arrangement etc.have been broadly explored using FLUENT simulation.To planning parameters,the Floor Area Ratio(FAR)is significantly influence wind environment,the smaller FAR is better.To the vertical layout of the buildings,multi-storey layout and multi-storey&sub high-rise mixed layout would provide better wind environment.To the horizontal layout,the determinant is better than the peripheral.Other factors such as the buildings’direction towards the road,buildings’height,and open space setting,have influence on wind environment yet.In general,the more benefit of design layout for wind breezing,the better wind environment it could get.展开更多
In the context of epidemic prevention and control,villages are the weakest part of epidemic prevention and control.Traditional villages,as representatives of villages,are often far away from cities,and medical conditi...In the context of epidemic prevention and control,villages are the weakest part of epidemic prevention and control.Traditional villages,as representatives of villages,are often far away from cities,and medical conditions are relatively backward.Based on this background,epidemic prevention and control are particularly important.The quality of the environment is positively related to the spread of the virus.This article wanted to use CFD technology to simulate the wind environment of the traditional village street space,so as to propose measures to optimize the wind environment of the traditional village street space,and provide references for the future planning of village layout.展开更多
Wind environment simulation of a commercial district in Baise city of Guangxi Province, China, is carried out in the design phase. The results are analyzed and based on the evaluation standard for greening building of...Wind environment simulation of a commercial district in Baise city of Guangxi Province, China, is carried out in the design phase. The results are analyzed and based on the evaluation standard for greening building of China. The simulation method is discussed in detail, and some suggestions for wind environment optimization are put forward, which might be helpful for similar research.展开更多
With the acceleration of urbanization,urban wind environment problems are becoming increasingly prominent,directly affecting air quality and residents’quality of life.The complex layout of old urban areas restricts w...With the acceleration of urbanization,urban wind environment problems are becoming increasingly prominent,directly affecting air quality and residents’quality of life.The complex layout of old urban areas restricts wind circulation and is prone to forming unfavorable wind environment zones.This study takes the old urban area within Hefei City Ring Park as the study area by selecting three representative blocks,establishes three-dimensional models,and employs Computational Fluid Dynamics(CFD)numerical simulation to analyze wind velocity distribution in the study area and the key influencing factors.Simulation results show that,influenced by a combination of multiple factors,the wind environment of the old urban area varies significantly.This study then proposes corresponding optimization strategies for the wind environment conditions of each block,such as adjusting the layout and form of target buildings,optimizing the layout of building clusters,increasing green spaces in the city,and improving the design of individual buildings.Comparing existing and optimized simulations validates the effectiveness of these strategies.Finally,the research compares the existing and optimized wind environment conditions,providing empirical support and scientific guidance for optimizing wind environments of old urban areas and promoting high-quality urban renewal practices.展开更多
The irregular shape of buildings always tenders an enormous challenge to the designers.The wind velocity at the pedestrian level has a specific approach from a comfortable point of view.This investigation highlighted ...The irregular shape of buildings always tenders an enormous challenge to the designers.The wind velocity at the pedestrian level has a specific approach from a comfortable point of view.This investigation highlighted the characteristic of the pedestrian level wind velocity for distinct types of asymmetrical setback buildings.The passed study explored the pedestrian level effect for the axisymmetric models,while this study is based on the models that have symmetry about a single axis.This study investigates the pedestrian level flow fluctuation of setback models with single and double side setbacks at multiple levels.The double-side double setback buildings are efficient to reduce 28%-30%velocity in front of the building and 68%-70%velocity behind the building.Finally it suggests that the double side double setback building is efficient to maintain the velocity at the pedestrian level,roof level,and backside of the building.The setback building can easily control the frequency of fluctuating velocity at downstream flow for both along and across wind conditions.展开更多
The Dunhuang–Golmud railway passes through different deserts in arid areas,especially drifting-sand desert and sandy-gravel Gobi.The near-surface wind environment and wind-sand transport process vary due to different...The Dunhuang–Golmud railway passes through different deserts in arid areas,especially drifting-sand desert and sandy-gravel Gobi.The near-surface wind environment and wind-sand transport process vary due to different external factors,such as topography,vegetation,and regional climate,resulting in evident spatial differences in surface erosion and deposition.Consequently,the measures for preventing wind-sand hazards will differ.However,the mechanism and control theory of sand damage remain poorly understood.In this study,we used meteorological observation,three-dimensional(3D)laser scanning,and grain-size analysis to compare and evaluate the spatial distribution of wind conditions,sand erosion and deposition patterns,and grain composition in the drifting-sand desert and sandy-gravel Gobi along the Dunhuang–Golmud railway in China.Results show that the annual mean wind speed,the frequency of sand-driving wind,and the drift potential of sandy-gravel Gobi are higher than those of drifting-sand desert,indicating a greater wind strength in the sandy-gravel Gobi,which exhibits spatial heterogeneity in wind conditions.The major sediment components in sandy-gravel Gobi are very fine sand,fine sand,and medium sand,and that in drifting-sand desert are very fine sand and fine sand.We found that the sediment in the sandy-gravel Gobi is coarser than that in the drifting-sand desert based on mean grain size and sediment component.The spatial distributions of sand erosion and deposition in the sandy-gravel Gobi and drifting-sand desert are consistent,with sand deposition mainly on the west side of the railway and sand erosion on the east side of the railway.The area of sand deposition in the drifting-sand desert accounts for 75.83%of the total area,with a mean deposition thickness of 0.032 m;while the area of sand deposition in the sandy-gravel Gobi accounts for 65.31%of the total area,with a mean deposition thickness of 0.028 m,indicating greater deposition amounts in the drifting-sand desert due to the presence of more fine sediment components.However,the sand deposition is more concentrated with a greater thickness on the embankment and track in the sandy-gravel Gobi and is dispersed with a uniform thickness in the drifting-sand desert.The sand deposition on the track of the sandy-gravel Gobi mainly comes from the east side of the railway.The results of this study are helpful in developing the preventive measures and determining appropriate selection and layout measures for sand control.展开更多
The wind environment around tall buildings in a central business district(CBD)was numerically investigated.The district covers an area of-^4.0 km2 and features a high density of tall buildings.In this study,only build...The wind environment around tall buildings in a central business district(CBD)was numerically investigated.The district covers an area of-^4.0 km2 and features a high density of tall buildings.In this study,only buildings taller than 20 m were considered,resulting in 173 tall buildings in the analysis.The numerical investigation was realized using the commercial computational fluid dynamics code FLUENT with the realizable A-6:turbulence model.Special efforts were made to maintain inflow boundary conditions throughout the computational domain.The reliability of the numerical method was validated using results from an experimental investigation conducted in the core area of the CBD(〜1.5 km2).Experimental and numerical investigations of wind speed ratios at the center of the three tallest buildings in the CBD agree within an uncertainty factor of 2.0.Both the experimental and numerical results show that wind speed ratios in the wind field with exposure category D are higher than those from the wind field with exposure category B.Based on the above validation work,the wind environment around tall buildings in the whole CBD was then investigated by numerical simulation.Common flow phenomena and patterns,such as stagnation points,shielding effects,separation flow,and channeling flow,were identified around the tall buildings.The pedestrianlevel wind environment around tall buildings in the CBD was further evaluated using nearby meteorological wind data.The evaluation results show that some pedestrian activities,such as sitting at the center of the three tallest buildings,are unadvisable when the wind blows from the south-east.展开更多
A computational model has been developed for the simulation of pedestrian level wind environment around tall buildings by coupling the numerical simulation of the full scale site and meteorological station materials...A computational model has been developed for the simulation of pedestrian level wind environment around tall buildings by coupling the numerical simulation of the full scale site and meteorological station materials. In the first step, the hybrid/mixed finite element method is employed to solve the two dimensional Navier Stokes equation for the flow field around tall buildings, in view of the influence of fluctuating wind, the flow field is revised with the effective wind velocity. The velocity ratio is defined in order to relate numerical wind velocity to oncoming reference wind velocity. In the second step, the frequency occurred discomfort wind velocity as a suitable criterion is calculated by use of the coupling between the numerical wind velocity and the wind velocity at the nearest meteorological station. The prediction accuracy of the wind environment simulation by use of the computation model will be discussed. Using the available wind data at the nearest meteorological station as well as the established criteria of wind discomfort, the frequency of wind discomfort can be predicted. A numerical example is given to illustrate the application of the proposed method.展开更多
This research arises from the need to investigate the phenomenon of the development of wind farms in Puglia and the aspects related to the environmental impact that these systems generate on the territory. This repres...This research arises from the need to investigate the phenomenon of the development of wind farms in Puglia and the aspects related to the environmental impact that these systems generate on the territory. This represents a sign of change and adaptation on landscapes for people and local governments. The demand and the need to install renewable energy systems must be mediated by the preservation of the landscape and governed by planning instruments, which in this case should be expanded with a strategic energy planning in the anthropized environment that is being examined. With a careful analysis of the current situation, this paper suggests, a model of integrated development in which technology, landscape and bureaucracy reach an almost perfect balance between the protection of the territory and the incessant vicious speculative and criminal process.展开更多
This paper briefs the background and process of setting-up andupdating of Environmental Wind Tunnel Laboratory of State Power Corporation,details the environmental wind tunnel, completed measuring instruments andequip...This paper briefs the background and process of setting-up andupdating of Environmental Wind Tunnel Laboratory of State Power Corporation,details the environmental wind tunnel, completed measuring instruments andequipment of the laboratory, and also describes the experimental projects thePower Environmental Protection Research Institute has completed, theexperiences gained and the services the Institute can provide in the future.[展开更多
The construction of wind power project is conducive to saving energy,reducing emissions and regulating energy structure. But it inevitably causes some impacts on the environment in the construction process. Because th...The construction of wind power project is conducive to saving energy,reducing emissions and regulating energy structure. But it inevitably causes some impacts on the environment in the construction process. Because that the height of wind power generator generally exceeds 100 m,and visual range in plain region is farther,it is necessary to scientifically and rationally evaluate and analyze landscape visual environment impact of wind power generator in plain region. One wind power farm project of Zhanjiang is located in typical plain region of Guangdong coast. Referring to traditional analytic method of landscape visual impact and comparing with actual situation for the same kind of project in the region,results show that it is ＂ extremely sensitive＂ area at 0- 2. 5 km from wind power generator, ＂ very sensitive＂ area at 2. 5- 5. 0 km, ＂ sensitive＂ area at 5- 10 km, ＂generally sensitive＂ area at 10- 20 km,and non-sensitive area outside 20 km.展开更多
文摘The wind environment serves as an important indicator of the comfort level of the human settlement environment.A favorable wind environment in courtyards can offer residents a better living and activity environment.Based on the Climatic Suitability Evaluating on Human Settlement,this study employs Computational Fluid Dynamics(CFD)simulation analysis to evaluate the wind environment comfort in rural courtyards,and elucidates the interactions between various factors influencing the courtyard wind environment and the courtyard wind environment.It is anticipated that the findings of this study will serve as a valuable reference for the renovation and new construction of rural houses,with a focus on optimizing the wind environment.
文摘With the increasing global demand for renewable energy,the application of photovoltaic power generation in mountainous areas is gradually increasing.However,the complex wind environment in mountainous areas poses severe challenges to the design and optimization of solar photovoltaic brackets.Traditional design methods are difficult to cope with the changeable wind speed and direction in mountainous areas,resulting in structural instability or material waste.Researchers have identified the key factors affecting wind response through parametric research and dynamic wind response analysis,so as to optimize the brackets design and improve its adaptability and stability in complex wind environments.In this paper,the complexity of wind speed,wind direction and turbulence characteristics in mountainous areas and their influence on brackets design are explored.Through static and dynamic wind load analysis,the geometrical shape and material selection of the bracket are optimized to enhance its wind resistance.The application of multi-objective optimization model and intelligent optimization algorithm provides an effective solution for the design of solar photovoltaic brackets,ensuring their safety and reliability in complex wind environments.
基金supported by the National Basic Research Program of China(2012CB026105)the National Natural Science Foundation of China(41201003,41071009)the China Postdoctoral Science Foundation(2012M52819)
文摘Disturbance in wind regime and sand erosion deposition balance may lead to burial and eventual vanishing of a site.This study conducted 3D computational fluid dynamics(CFD)simulations to evaluate the effect of a proposed city design on the wind environment of the Crescent Spring,a downwind natural heritage site located in Dunhuang,Northwestern China.Satellite terrain data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)Digital Elevation Model(DEM)were used to construct the solid surface model.Steady-state Reynolds Averaged Navier-Stokes equations(RANS)with shear stress transport(SST)k-ωturbulence model were then applied to solve the flow field problems.Land-use changes were modeled implicitly by dividing the underlying surface into different areas and by applying corresponding aerodynamic roughness lengths.Simulations were performed by using cases with different city areas and building heights.Results show that the selected model could capture the surface roughness changes and could adjust wind profile over a large area.Wind profiles varied over the greenfield to the north and over the Gobi land to the east of the spring.Therefore,different wind speed reduction effects were observed from various city construction scenarios.The current city design would lead to about 2 m/s of wind speed reduction at the downwind city edge and about 1 m/s of wind speed reduction at the north of the spring at 35-m height.Reducing the city height in the north greenfield area could efficiently eliminate the negative effects of wind spee.By contrast,restricting the city area worked better in the eastern Gobi area compared with other parts of the study area.Wind speed reduction in areas near the spring could be limited to 0.1 m/s by combining these two abatement strategies.The CFD method could be applied to simulate the wind environment affected by other land-use changes over a large terrain.
基金Sponsored bythe National Project of Scientific and Technical Supporting Programs Funded by Ministry of Science & Technology of China(Grant No.2013BAJ12B02)the Fundamental Research Funds for the Central Universities(Grant No.HIT.KISTP.201419)
文摘To improve the outdoor environment of rural settlement and reduce the energy consumption of rural houses in winterin cold areas,the seriously bad wind environment should been controlled and considered. This paper applies the method of numerical simulation to simulate the wind environment of some typical arrangement of building and courtyard in winter,and concludes the optimal building and courtyard arrangement types and strategies. It aims to provide some technical supports for improving the wind environment of rural settlements in cold regions.
基金Sponsored by the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20122302110041)National Natural Science Foundation of China(Grant No.51378136)the Fundamental Research Funds for the Central Universities(Grant No.HIT.KISTP.201419)
文摘The wind environment around residential building groups is increasingly concerned,while the dwelling groups as the elementary unit of planning design,its quality of surrounding wind environment will directly affect people's life. This study based on the climatic conditions of severe cold regions,selects four dwellings groups with different openings scale and position as the research objects,and then simulates and analyzes the wind speed distribution characteristics of each pattern. Meanwhile,it extracts the wind speed values of one hundred points of each pattern and applies the coefficient of uniformity method to the ecological evaluation. It has been found that grouping pattern of buildings has a dramatic effect on the resulting airflow behavior. Configurations that contain a T-shaped central space with small opened side can effectively prevent and contain airflow in the site offer. The interactive influence between layout of dwelling groups and wind environment are explored,so as to provide basis for the planning design of dwelling groups.
基金This work was supported by the National Natural Science Foundation of China(No.51976139).
文摘Computational fluid dynamics(CFD)has become the main method for the prediction of the properties of the external wind environment in cities and other urban contexts.A review is presented of the existing literature in terms of boundary conditions,building models,computational domains,computational grids,and turbulence models.Some specific issues,such as the accuracy/computational cost ratio and the exploitation of existing empirical correlations,are also examined.
文摘It is important to improve residential thermal comfort in the high dense cities,in which wind environment is crucial.Waterside buildings take an advantage of micro-hydrological-climate in summer that should be used to enhance residential thermal comfort especially in the subtropical region.In order to propose design approaches according to the outdoor thermal comfort of the waterside residential,a case study of Shenzhen She Kou residential district has been made.It focused on various factors that could have influence on wind environment for improving thermal comfort.Using wind velocity ratio(ΔRi)criterion,factors of building development volume,building direction and layout pattern,open space arrangement etc.have been broadly explored using FLUENT simulation.To planning parameters,the Floor Area Ratio(FAR)is significantly influence wind environment,the smaller FAR is better.To the vertical layout of the buildings,multi-storey layout and multi-storey&sub high-rise mixed layout would provide better wind environment.To the horizontal layout,the determinant is better than the peripheral.Other factors such as the buildings’direction towards the road,buildings’height,and open space setting,have influence on wind environment yet.In general,the more benefit of design layout for wind breezing,the better wind environment it could get.
基金Sponsored by Sci-Tech Support Program of Hebei Provincial Department of Science and Technology(16236004D-9)Social Sciences Foundation of Hebei Province(HB15YS070)。
文摘In the context of epidemic prevention and control,villages are the weakest part of epidemic prevention and control.Traditional villages,as representatives of villages,are often far away from cities,and medical conditions are relatively backward.Based on this background,epidemic prevention and control are particularly important.The quality of the environment is positively related to the spread of the virus.This article wanted to use CFD technology to simulate the wind environment of the traditional village street space,so as to propose measures to optimize the wind environment of the traditional village street space,and provide references for the future planning of village layout.
文摘Wind environment simulation of a commercial district in Baise city of Guangxi Province, China, is carried out in the design phase. The results are analyzed and based on the evaluation standard for greening building of China. The simulation method is discussed in detail, and some suggestions for wind environment optimization are put forward, which might be helpful for similar research.
文摘With the acceleration of urbanization,urban wind environment problems are becoming increasingly prominent,directly affecting air quality and residents’quality of life.The complex layout of old urban areas restricts wind circulation and is prone to forming unfavorable wind environment zones.This study takes the old urban area within Hefei City Ring Park as the study area by selecting three representative blocks,establishes three-dimensional models,and employs Computational Fluid Dynamics(CFD)numerical simulation to analyze wind velocity distribution in the study area and the key influencing factors.Simulation results show that,influenced by a combination of multiple factors,the wind environment of the old urban area varies significantly.This study then proposes corresponding optimization strategies for the wind environment conditions of each block,such as adjusting the layout and form of target buildings,optimizing the layout of building clusters,increasing green spaces in the city,and improving the design of individual buildings.Comparing existing and optimized simulations validates the effectiveness of these strategies.Finally,the research compares the existing and optimized wind environment conditions,providing empirical support and scientific guidance for optimizing wind environments of old urban areas and promoting high-quality urban renewal practices.
文摘The irregular shape of buildings always tenders an enormous challenge to the designers.The wind velocity at the pedestrian level has a specific approach from a comfortable point of view.This investigation highlighted the characteristic of the pedestrian level wind velocity for distinct types of asymmetrical setback buildings.The passed study explored the pedestrian level effect for the axisymmetric models,while this study is based on the models that have symmetry about a single axis.This study investigates the pedestrian level flow fluctuation of setback models with single and double side setbacks at multiple levels.The double-side double setback buildings are efficient to reduce 28%-30%velocity in front of the building and 68%-70%velocity behind the building.Finally it suggests that the double side double setback building is efficient to maintain the velocity at the pedestrian level,roof level,and backside of the building.The setback building can easily control the frequency of fluctuating velocity at downstream flow for both along and across wind conditions.
基金This research was supported by the National Natural Science Foundation of China(42171083,41871016)the Natural Science Foundation of Gansu Province,China(22JR5RA066).
文摘The Dunhuang–Golmud railway passes through different deserts in arid areas,especially drifting-sand desert and sandy-gravel Gobi.The near-surface wind environment and wind-sand transport process vary due to different external factors,such as topography,vegetation,and regional climate,resulting in evident spatial differences in surface erosion and deposition.Consequently,the measures for preventing wind-sand hazards will differ.However,the mechanism and control theory of sand damage remain poorly understood.In this study,we used meteorological observation,three-dimensional(3D)laser scanning,and grain-size analysis to compare and evaluate the spatial distribution of wind conditions,sand erosion and deposition patterns,and grain composition in the drifting-sand desert and sandy-gravel Gobi along the Dunhuang–Golmud railway in China.Results show that the annual mean wind speed,the frequency of sand-driving wind,and the drift potential of sandy-gravel Gobi are higher than those of drifting-sand desert,indicating a greater wind strength in the sandy-gravel Gobi,which exhibits spatial heterogeneity in wind conditions.The major sediment components in sandy-gravel Gobi are very fine sand,fine sand,and medium sand,and that in drifting-sand desert are very fine sand and fine sand.We found that the sediment in the sandy-gravel Gobi is coarser than that in the drifting-sand desert based on mean grain size and sediment component.The spatial distributions of sand erosion and deposition in the sandy-gravel Gobi and drifting-sand desert are consistent,with sand deposition mainly on the west side of the railway and sand erosion on the east side of the railway.The area of sand deposition in the drifting-sand desert accounts for 75.83%of the total area,with a mean deposition thickness of 0.032 m;while the area of sand deposition in the sandy-gravel Gobi accounts for 65.31%of the total area,with a mean deposition thickness of 0.028 m,indicating greater deposition amounts in the drifting-sand desert due to the presence of more fine sediment components.However,the sand deposition is more concentrated with a greater thickness on the embankment and track in the sandy-gravel Gobi and is dispersed with a uniform thickness in the drifting-sand desert.The sand deposition on the track of the sandy-gravel Gobi mainly comes from the east side of the railway.The results of this study are helpful in developing the preventive measures and determining appropriate selection and layout measures for sand control.
基金This research was supported by the Ministry of Science and Technology of the People’s Republic of China(Grant Nos.2015CB452806 and 2018YFB1501104)the National Natural Science Foundation of China(Grant No.51408196)+1 种基金the Natural Science Foundation of Shanghai(Grant No.19ZR1469200).Further support was provided by the State Key Laboratory for Disaster Reduction in Civil Engineering(No.SLDRCE15-A-04)the Study on the Wind Characteristics Caused by Typhoons Considering Offshore Wind Farm Safety along Fujian Province(No.2016FD(8)-008).The authors are indebted to the anonymous reviewers who provided valuable suggestions that improved the manuscript,particularly scientific aspects.
文摘The wind environment around tall buildings in a central business district(CBD)was numerically investigated.The district covers an area of-^4.0 km2 and features a high density of tall buildings.In this study,only buildings taller than 20 m were considered,resulting in 173 tall buildings in the analysis.The numerical investigation was realized using the commercial computational fluid dynamics code FLUENT with the realizable A-6:turbulence model.Special efforts were made to maintain inflow boundary conditions throughout the computational domain.The reliability of the numerical method was validated using results from an experimental investigation conducted in the core area of the CBD(〜1.5 km2).Experimental and numerical investigations of wind speed ratios at the center of the three tallest buildings in the CBD agree within an uncertainty factor of 2.0.Both the experimental and numerical results show that wind speed ratios in the wind field with exposure category D are higher than those from the wind field with exposure category B.Based on the above validation work,the wind environment around tall buildings in the whole CBD was then investigated by numerical simulation.Common flow phenomena and patterns,such as stagnation points,shielding effects,separation flow,and channeling flow,were identified around the tall buildings.The pedestrianlevel wind environment around tall buildings in the CBD was further evaluated using nearby meteorological wind data.The evaluation results show that some pedestrian activities,such as sitting at the center of the three tallest buildings,are unadvisable when the wind blows from the south-east.
文摘A computational model has been developed for the simulation of pedestrian level wind environment around tall buildings by coupling the numerical simulation of the full scale site and meteorological station materials. In the first step, the hybrid/mixed finite element method is employed to solve the two dimensional Navier Stokes equation for the flow field around tall buildings, in view of the influence of fluctuating wind, the flow field is revised with the effective wind velocity. The velocity ratio is defined in order to relate numerical wind velocity to oncoming reference wind velocity. In the second step, the frequency occurred discomfort wind velocity as a suitable criterion is calculated by use of the coupling between the numerical wind velocity and the wind velocity at the nearest meteorological station. The prediction accuracy of the wind environment simulation by use of the computation model will be discussed. Using the available wind data at the nearest meteorological station as well as the established criteria of wind discomfort, the frequency of wind discomfort can be predicted. A numerical example is given to illustrate the application of the proposed method.
文摘This research arises from the need to investigate the phenomenon of the development of wind farms in Puglia and the aspects related to the environmental impact that these systems generate on the territory. This represents a sign of change and adaptation on landscapes for people and local governments. The demand and the need to install renewable energy systems must be mediated by the preservation of the landscape and governed by planning instruments, which in this case should be expanded with a strategic energy planning in the anthropized environment that is being examined. With a careful analysis of the current situation, this paper suggests, a model of integrated development in which technology, landscape and bureaucracy reach an almost perfect balance between the protection of the territory and the incessant vicious speculative and criminal process.
文摘This paper briefs the background and process of setting-up andupdating of Environmental Wind Tunnel Laboratory of State Power Corporation,details the environmental wind tunnel, completed measuring instruments andequipment of the laboratory, and also describes the experimental projects thePower Environmental Protection Research Institute has completed, theexperiences gained and the services the Institute can provide in the future.[
文摘The construction of wind power project is conducive to saving energy,reducing emissions and regulating energy structure. But it inevitably causes some impacts on the environment in the construction process. Because that the height of wind power generator generally exceeds 100 m,and visual range in plain region is farther,it is necessary to scientifically and rationally evaluate and analyze landscape visual environment impact of wind power generator in plain region. One wind power farm project of Zhanjiang is located in typical plain region of Guangdong coast. Referring to traditional analytic method of landscape visual impact and comparing with actual situation for the same kind of project in the region,results show that it is ＂ extremely sensitive＂ area at 0- 2. 5 km from wind power generator, ＂ very sensitive＂ area at 2. 5- 5. 0 km, ＂ sensitive＂ area at 5- 10 km, ＂generally sensitive＂ area at 10- 20 km,and non-sensitive area outside 20 km.
