WIND DESCRIPTION/ENERGY CONTENT

Turbulence


Short term variability in the air         
Short term variability of wind         Hailstorms or thunderstorms in particular, are associated with frequent gusts of wind which both change speed and direction. In areas with a very uneven terrain surface and behind obstacles, such as buildings, there is similarly created a lot of turbulence, with very irregular wind flows, often in whirls or vortexes in the neighbourhood.
        An example of how turbulence increases the fluctuations in the wind speed is shown in the image, which may be compared with the image on the previous page. Turbulence decreases the possibility of using the energy in the wind effectively for a wind turbine. It also imposes more tear and wear on the wind turbine, as it will be explained in the page on fatigue loads. Towers for wind turbines are usually made tall enough to avoid turbulence from the wind close to ground level.
        







Video frames
- Turbulence (A): definition, equations
- Turbulence (B): common values of turbulence
- Turbulence (C): turbulence in (offshore) wind farms


Handouts
- Climate and turbulence