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1.Climate as a Public Interest in Planning and Zoning
2.Characteristics and Forms of the Urban Climate
3.Energy-Conscious Planning and Zoning
4.Methods of Information Acquisition for Planning (Measurements, Wind Tunnels, Numerical Modelling)
4.1Measurements
4.1.1Stationary Measurements
4.1.2Measurements with mobile measurement devices
4.1.3Tracer Experiments
4.1.4Vertical Soundings
4.2Wind Tunnel
4.2.1Overview
4.2.2Operation and Investigation Methods
4.2.2.1Visualization of flows and pollutant dispersion by smoke
4.2.2.2Wind Velocity Measurements
4.2.2.3Measurement of Concentration Distribution in Dispersal Experiments
4.2.3Locations of Wind Tunnels
4.3Numerical Modelling of Flow and Transport Processes
4.3.1The Wind Field Model DIWIMO
4.3.2The Cold-Air Flow Model KALM and KLAM 21
4.3.3The Model STREET for Estimating Traffic-Produced Pollution
4.3.4The Model MLuS-02 for Calculating Pollutant Dispersal
on Roads Without Dense Peripheral Development
4.3.5The Model PROKAS for Calculating Air Pollution on Roads
4.3.6The Micro-Scale Model MISKAM
4.3.7Mesoscale Terrain Climatic Models
4.3.8The Urban Climate Models RayMan , ENVI-met and MUKLIMO_3
5.Climatic and Air Hygiene Maps as Aids for Planning and Zoning (Example: Climate Atlas Federation Region Stuttgart)
6.Recommendations for Planning
7.Bibliography
8.Thematic Websites
Imprint
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METHODS OF INFORMATION ACQUISITION FOR PLANNING (MEASUREMENTS, WIND TUNNELS, NUMERICAL MODELLING)
   
 4.2.2.2 Wind Velocity Measurements

Changes in the wind field, such as those that can be caused by buildings, can be studied in simple form through sand erosion measurements. In these, the physical model is sprinkled with sand and the erosion is registered under various strengths of wind velocity blown at the model. From this, data are collected about the areas in the vicinity of a building where the wind velocity decreases or increases (Figure. 4/11).

For an exact determination of flow velocities and their rapid temporal changes, hot-wire or laser Doppler anemometers (LDA) are used for example. As hot-wire anemometers are rather small in size, they can be easily placed in a model (Fig. 4/12, left side). Laser Doppler anemometers allow for a non-contact operation (Fig. 4/12, right side). Both systems are characterised by short reaction times, which qualifies them for generating speed time series in the wind tunnel.

  
 
 
Fig. 4/11: Visualization increased wind speeds by sand erosion studies,
Source: BLAZEK et al , 1998
 
Fig. 4/12: left : hot wire anemometer in street canyon , Source: Engineering Office Theurer
right : laser Doppler anemometer Source: University of Hamburg , Institute Meteorological