Characteristics of the Wind - Wind Turbine Technology: Fundamental Concepts of Wind Turbine Engineering - page 513

The coefficient of 1.50 in Equations (8-29) has been selected in order to fit the simpler
Dryden functions to the von Karman functions, eliminating the need for the more-complex
Equations (8-28). The three pairs of correlation functions are plotted in Figure 8-23. In
Figure 8-23(a), the data points represent experimental longitudinal correlation coefficients
computed from wind speeds measured simultaneously along a line of anemometer towers
[Steely and Frost 1981]. Additional experimental data and discussion of spatial correlations
and integral length scales are given in Frost and Lin [1983] and Frost et al. [1985]. The
integral length scale, Z , is defined as the integral of the correlation coefficient over all
Figure 8-23. Three models of turbulence correlation coefficients. The Dryden model
has been fitted to the von Karman. (a) Longitudinal correlation coefficients compared to
test data (b) Transverse correlation coefficients