Analyses on a flow around a rectangular cube set on the floor in a wind tunnel are described. The study has been carried out using a particle image velocimetry (PIV) and a two-dimensional laser Doppler anemometry (2D-LDA) with fiber optics. At the inlet, the mean flow velocity and the relative turbulence intensity are 4.0 m/s and 1.5%, respectively in the experiments. Under this condition, the flow Reynolds number based on the rectangular cube height and the mean velocity is about 8.8 × 10³. Firstly, comparisons between the LDA and PIV results are made about the mean velocity, turbulent intensity and Reynolds stress. Secondly, the influences of the size of interrogation area in PIV measurement are discussed. Finally, the visualizations of vortices distributions are performed by the Reynolds decomposition and the Galilean decomposition methods, which use the instantaneous and the averaged velocity fields obtained by PIV measurements.

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