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This study leverages a novel multi-fan flow-control instrument and a mechanized roughness element grid to simulate large- and small-scale turbulent features of atmospheric flows in a large boundary layer wind tunnel (BLWT). The flow-control instrument, termed the flow field modulator (FFM), is a computer-controlled 3 m × 6 m (2D) fan array located at the University of Florida (UF) Natural Hazard Engineering Research Infrastructure (NHERI) Experimental Facility. The system comprises 319 modular hexagonal aluminum cells, each equipped with shrouded three-blade corotating propellers. The FFM enables the active generation of large-scale turbulent structures by replicating user-specified velocity time signals to inject low-frequency fluctuations into BLWT flows. In the present work, the FFM operated in conjunction with a mechanized roughness element grid, called the Terraformer, located downstream of the FFM array. The Terraformer aided in the production of near-wall turbulent mixing through precise adjustment of the height of the roughness elements. A series of BLWT velocity profile measurement experiments were carried out at the UF BLWT test section for a set of turbulence intensity and integral length scale regimes. Input commands to the FFM and Terraformer were iteratively updated via a governing convergence algorithm (GCA) to achieve user-specified mean and turbulent flow statistics. Results demonstrate the capabilities of the FFM for significantly increasing the longitudinal integral length scales compared to conventional BLWT approaches (i.e., no active large-scale turbulence generation). The study also highlights the efficacy of the GCA scheme for attaining prescribed target mean and turbulent flow conditions at the measurement location. 

This dataset includes flow velocity time series collected in a large boundary layer wind tunnel (BLWT) to investigate the intensity of large-scale turbulent gust structures generated by a novel flow-control instrument. The work leveraged a multi-stage flow conditioning system consisting of an active multi-fan gust generator, termed flow field modulator (FFM), that operated in conjunction with an automated roughness element grid (called Terraformer). The primary goal of the study is to assess the effectiveness of the coupled flow conditioning system (FFM and Terraformer) for increasing and tuning large-scale (particularly near-surface) turbulent structures that will enable characterization of their impact on building loads at relatively large BLWT scales (1:50). The dataset can be used and compared against previously published velocity measurements collected using traditional BLWT flow conditioning approaches (i.e., no active control of large-scale turbulence).