• The turbulence intensity Iv(z) at height z is calculated automatically.

  • Turbulence factor kl and orography factor co(z) values are defined by user.


Notation

co(z) = Orography factor
Iv(z) = Turbulence intensity
kl = Turbulence factor
kr = Terrain factor depending on the roughness length
vb = Basic wind velocity
vm(z) = The mean wind velocity
zmin = Minimum height
zo = Roughness length
σv = Standard deviation of the turbulence


The turbulence intensity Iv(z) at height z is defined as the standard deviation of the turbulence divided by the mean wind velocity. The turbulence intensity Iv(z) is calculated using equation below.

The standard deviation of the turbulence σv is calculated using equation below.

Terrain factor kr and basic wind velocity, vb are defined in the Mean Wind title.

Turbulence factor kl may be given in the National Annex. The recommended value for kl is 1,0.

Orography factor co(z) is defined by user.

Roughness length zo is given in EN 1991-1-4 Table 4.1.


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