LDV measurements and analysis of pulsating velocity characteristics in a flat plate turbulent boundary layer

The study of the characteristics of the pulsating velocity distribution in a flat plate turbulent boundary layer is important for the development of pulsating velocity turbulence models. In this paper, high temporal and spatial resolution measurements of velocity pulsations within the boundary layer of a flat plate turbulence are carried out in a wind tunnel using a laser Doppler velocimeter (LDV). By analyzing the measurement results, a mean velocity distribution curve is obtained, which is consistent with the turbulent velocity distribution curve given by other studies, confirming that the experimental setup of measuring the velocity in the flat plate boundary layer using LDV is reliable in this experiment. The analysis of the statistical results of the pulsation velocity reveals that the root mean square distribution of the pulsation velocity has a distinct inner peak and a small outer peak within the boundary layer, which is consistent with the results of recent studies and further characterizes the distribution of the pulsation velocity within the boundary layer. At the same time, the spectral analysis of the pulsation velocity reveals that the pulsation characteristics in different regions of the boundary layer are different, the pulsation amplitude in the logarithmic law region fluctuates from high to low, and the pulsation in the outer layer of the boundary layer appears to be intermittent.