Advanced nonhomogeneous wind field simulation for offshore Turbines via enhanced A-R scheme

The precise and efficient simulation of the spatial variable wind field is the underpinning of the dynamic response analysis of the wind turbine structure. The evolutionary frequency-wavenumber spectrum-based spectral representation method circumvents the computational overhead associated with Cholesky decomposition. However, challenges persist; notably, simulation efficiency may fall short of optimal levels, and demanding computational specifications are mandated. This study addresses these concerns through the introduction of an improved uneven discretization strategy, denoted as enhanced acceptance-rejection scheme, tailored for two-spatial dimensional nonhomogeneous wind fields. The proposed scheme commences by uniformly discretized frequency domain, followed by an uneven discretization of the wavenumber domain at each frequency achieved through the incorporation of introducing the acceptance-rejection method. This dual discretization approach, coupled with variability of the frequency-wavenumber spectrum with altitude, culminates in a scenario where the FFT is solely applied along the frequency dimension, vastly streamlining computations. In addition, a numerical case study is presented to scrutinize the impact of the frequency-wavenumber spectrum at different altitudes as an acceptance-rejection criterion. 1024 sets of 7×106 Sobol’ points are generated, and only 1.32×105 representation points are retained. The comparison of the computational time between the original acceptance-rejection scheme and the enhanced scheme reveals that the simulation efficiency of the proposed method has been improved more than ten times.