Wind Climate in Cities

If one surveys the development of wind engineering, one comes to the conclusion that the challenge of urban climatology is one of the most important remaining tasks for the wind engineers. But what distinguishes wind engineering in urban areas from conventional wind engineering? Principally, the fact that the effects studied are usually unique to a particular situation, requiring consideration of the surroundings of the buildings. In the past, modelling criteria have been developed that make it possible to solve environmental problems with great confidence, and studies validated the models: at least in a neutrally stratified atmosphere. The approach adopted in the book is that of applied fluid mechanics, since this forms the basis for the evaluation of the urban wind field. Variables for air quality or loads are problem specific, or even random, and methods for studying them are based on risk analysis, which is also presented. Criteria are developed for a systematic approach to urban wind engineering problems, including parameter studies. The five sections of the book are: Fundamentals of urban boundary layer and dispersion; Forces on complex structures in built-up areas; Air pollution in cities; Numerical solution techniques; and Posters. A subject index is included. Front Matter....Pages i-xxii The Risk of Wind Effects in Cities....Pages 1-20 Front Matter....Pages 21-22 Urban Climates and Urban Climate Modelling: An Introduction....Pages 23-39 Atmospheric Boundary Layer and Its Parameterization....Pages 41-66 Scaling for Convective Boundary Layers....Pages 67-79 The Heat Island of the Urban Boundary Layer: Characteristics, Causes and Effects....Pages 81-107 Atmospheric Flow through Groups of Buildings and Dispersion from Localised Sources....Pages 109-130 Physical Modelling of Atmospheric Dispersion in Complex Settings....Pages 131-152 Analysis of Meteorological Data and Main Problems Related to the Determination of Building Exposure....Pages 153-182 Front Matter....Pages 183-184 Local Wind Pressures for Rectangular Buildings in Turbulent Boundary Layers....Pages 185-207 The Response of Slender Structures to Wind....Pages 209-239 Wind Loads on Structures from Eurocode 1, ENV 1991-2-3....Pages 241-258 Interference Effects on Flexible Buildings and Structures....Pages 259-273 Wind-Induced Response of Buildings Arranged in a Group....Pages 275-292 The Influence of Surroundings on Pressure Distributions around Buildings....Pages 293-317 Winds in Cities: Effects on Pedestrians and the Dispersion of Ground Level Pollutants....Pages 319-335 Damage to Buildings by Storms in Urban Areas....Pages 337-350 Front Matter....Pages 351-351 Urban Climates and Air Pollution in Small Swiss Cities....Pages 353-382 Physical Modelling of Flow and Dispersion over Urban Areas....Pages 383-403 A Laboratory Simulation of Urban Heat-Island-Induced Circulation in a Stratified Environment....Pages 405-429 Wind Tunnel Modelling of Convective Boundary Layers....Pages 431-456 Front Matter....Pages 351-351 Concentration Fluctuations in Plumes: Observations and Models....Pages 457-484 Point Sources in Urban Areas: Modelling of Neutral Gas Clouds with Semi-empirical Models....Pages 485-502 Convective Heat Losses from Buildings....Pages 503-522 Traffic Induced Pollution: Diffusion in the Neighbourhood of Tunnels and Streets....Pages 523-534 Traffic Induced Pollution: How to Evaluate Wind Tunnel Data for Municipal Dicision Makers....Pages 535-546 Modelling of Motor Vehicle Immissions in a Street System by Combination of Lagrange Models and Surface Wind Field Simulation in Complex City Structures....Pages 547-553 Accidental Releases of Heavy Gases in Urban Areas....Pages 555-574 Dense Gas Dispersion in Complex Settings: Part 1 — The Effect of Obstacles....Pages 575-605 Dense Gas Dispersion in Complex Settings: Part 2 — The Effect of Topography....Pages 607-629 Front Matter....Pages 631-632 Introduction to the Numerical Simulation Approaches in Wind Engineering....Pages 633-647 Simulation of Flow Past Buildings with Statistical Turbulence Models....Pages 649-668 Large-Eddy-Simulation of the Three-Dimensional Flow around Buildings....Pages 669-679 Numerical Simulation of Turbulent Diffusion in Cities....Pages 681-701 Applications of the RAMS Numerical Model to Dispersion over Urban Areas....Pages 703-732 Front Matter....Pages 733-733 Simulating the Effects of Stable Stratification on Flow and Dispersion around a Cubical Building....Pages 735-735 Numerical Simulation of Steep Terrain Influences on Flow Patterns at the Isle of Helgoland....Pages 737-737 Reduction of Horizontal Wind Speed in a Boundary Layer with Obstacles....Pages 739-739 Dependence of Scaling for a Convective Atmospheric Surface Layer on Size of Turbulent Disturbances....Pages 741-746 Wind Research Climate at Texas Tech University — An Overview....Pages 747-748 Automatic Linking of Three-Dimensional Models with Different Grid Granularity....Pages 749-749 Front Matter....Pages 733-733 An IBL Experiment over Athens Urban Area....Pages 751-751 Wind Resistance Categorization of Buildings....Pages 753-753 Numerical Experiments on Urban Heat Island Intensity....Pages 755-755 PBL Observations and Measurements in the Area of Rome....Pages 757-757 Back Matter....Pages 759-772 The Risk of Wind Effects in Cities Urban Climates and Urban Climate Modelling: An Introduction Atmospheric Boundary Layer and its Parameterization Scaling for Convective Boundary Layers The Heat Island of the Urban Boundary Layer: Characteristics, Causes and Effects Atmospheric Flow through Groups of Buildings and Dispersion from Localised Sources Physical Modelling of Atmospheric Dispersion in Complex Settings Analysis of Meteorological Data and Main Problems Related to the Determination of Building Exposure Local Wind Pressures for Rectangular Buildings in Turbulent Boundary Layers The Response of Slender Structures to Wind Wind Loads on Structures from EUROCODE 1, ENV 1991-2-3 Interference Effects on Flexible Buildings and Structures Wind-induced Response of Buildings Arranged in a Group The Influence of Surroundings on Pressure Distributions around Buildings ^ Wind in Cities: Effects on Pedestrians and the Dispersion of Ground Level Pollutants Damage to Buildings by Storms in Urban Areas Urban Climates and Air Pollution in Small Swiss Cities Physical Modelling of Flow and Dispersion over Urban Areas A Laboratory Simulation of Urban Heat — Island — Induced Circulation in a Stratified Environment Wind Tunnel Modelling of Convective Boundary Layers Concentration Fluctuations in Plumes: Observations and Models Point Sources in Urban Areas: Modelling of Neutral Gas Clouds with Semi-empirical Models Convective Heat Losses from Buildings Traffic Induced Pollution: Diffusion in the Neighbourhood of Tunnels and Streets Traffic Induced Pollution: How to Evaluate Wind Tunnel Data for Municipal Decision Makers Modelling of Motor Vehicle Immissions in a Street System by Combination of Lagrange Models and Surface Wind Field Simulation in Complex City Structures Accidental Releases of Heavy Gases in Urban Areas ^ ^^ Dense Gas Dispersion in Complex Settings: Part 1 — The Effect of Obstacles Dense Gas Dispersion in Complex Settings: Part 2 — The Effect of Topography to the Numerical Simulation Approaches in Wind Engineering Simulation of Flow past Buildings with Statistical Turbulence Models Large-Eddy-Simulation of the Three-dimensional Flow around Buildings Numerical Simulation of Turbulent Diffusion in Cities Application of the RAMS Numerical Model to Dispersion over Urban Areas Simulating the Effects of Stable Stratification on Flow and Dispersion around a Cubical Building Numerical Simulation of Steep Terrain Influences on Flow Patterns at the Isle of Helgoland Reduction of Horizontal Wind Speed in a Boundary Layer with Obstacles Dependence of Scaling for a Convective Atmospheric Surface Layer on Size of Turbulent Disturbances Wind Research Climate at Texas Tech University — An Overview ^ ^^ Automatic Linking of Three-dimensional Models with Different Grid Granularity An IBL Experiment over Athens Urban Area Wind Resistance Categorization of Buildings Numerical Experiments on Urban Heat-Island Intensity PBL Observations and Measurements in the Area of Rome List of Contributors. ^^ Proceedings of the NATO Advanced Study Institute, Waldbronn, Germany, July 5--16, 1993