Effects of turbulent intensities on the boundary layer development

With Laser Doppler Velocimeter (LDV) and hydrogen bubble visualization techniques, the detailed measurement and observations have been carried out for the development of boundary layer flow over a flat plate. The effects of turbulent intensities on the boundary layer transition and on the characteristics of the turbulent boundary layer are investigated, and the criteria to divide the laminar boundary layer, the transitional region and the turbulent boundary layer are obtained. In the present experiments, it is found that the turbulent intensities have significant influence on the boundary layer transition and less influence on the characteristics of the turbulent boundary layer.