• The basic wind velocity vb value is defined by user.


Notation

cdir = Directional factor
cseason = Season factor
vb = Basic wind velocity
vb,0 = Fundemantal value of the basic wind velocity


The fundamental value of the basic wind velocity, vb,0, is the characteristic 10 minutes mean wind velocity, irrespective of wind direction and time of year, at 10m above ground level in open country terrain with low vegetation such as grass and isolated obstacles with separations of at least 20 obstacle heights.

The fundamental value of the basic wind velocity, vb,0 , may be given in the National Annex.

The basic wind velocity vb

The value of the directional factor, cdir, for various wind directions may be found in the National Annex. The recommended value is 1,0.

The value of the season factor, cseason, may be given in the National Annex. The recommended value is 1,0.