Torque fluctuations in the framework of a multifractal 23/9-dimensional turbulence model

Abstract

We have carried out in-depth analyses of boundary-layer wind velocity data within a universal multifractal (UM) framework. Within the UM framework the statistics of a given field are characterised with the help of the three parameters α, C1 and H. With these three parameters one fully describes the wind velocity fields up to and including the order qD after which the divergence of statistical moments intervenes. Studies at different sites have shown that the parameter α-the multifractality index-of the horizontal and vertical shears of the horizontal wind remains fairly constant at approximately 1.7. In this study we show how the two remaining parameters C1 and H vary for two very different sites/datasets and discuss what the consequences of this variability are for the fluctuations of the torque.