Example For Logarithmic Wind Profile Fit
WindDataSuite implements a module for fitting measured wind speed data
to logarithmic wind speed profiles in analogy to the
atmospheric boundary layer theory.
The fitting can be calculated for the 2parameter model (friction
velocity u_{*}, roughness length z_{0}) and for the
3parameter model (friction velocity u_{*}, roughness length z_{0},
displacement height D).
Besides the classical method using linear regression,
the logarithmic wind speed profile can also be calculated by
using an 1dimensional flow model. The linear regression
is a pure mathematical fitting, whereas the 1dimensional
flow model will use all available relevant measured data
in order to determine the actual physical processes
within the air column.
In the following example, the height profiles of the measured
wind speeds (black curves) have been fitted to the logarithmic
wind speed profile (3parameter model, red curves).
The results from the linear regression are depicted in Fig.1,
the results from the 1dimensional flow model in Fig.2,
respectively at two consecutive time steps.


Fig.1: Logarithmic wind profile fit, 3parameter model, linear regression



Fig.2: Logarithmic wind profile fit, 3parameter model, 1D flow model

;
Data range

:

1 year (365 days), sampling rate 10 minutes

Processed channels

:

31 height levels of wind speed
31 height levels of vertical wind velocity
31 height levels of wind direction

Computing time

:

approx. 10 seconds

Processing time

:

approx. 1 minute

