Effects of the Gortler vortices on turbulent boundary layer

The interaction between the Gortler vortices originated from an instability of turbulent boundary layer which developed on the contraction wall and the turbulent boundary layer on a measuring flat plate was examined experimentally. For the nominally two-dimensional turbulent boundary layer developing on a plate with three types of leading edge shape, the spatial variations of boundary layer characteristics and the streamwise variation of the spanwise mean values of the time-mean velocity and the fluctuating velocity were measured. The procedure of obliteration of spanwise variations due to the Gortler vortices were also attempt. From these results, it was revealed that the boundary layer exhibited a variation of characteristics in the spanwise direction, and its spatial fluctuating intensity was about (10)^<-2>×U_e. In addition, equilibrium boundary layer was not still realized within the present experimental range, and the spanwise variations of boundary layer characteristics due to the Gortler vortices were able to eliminate by use of the vortex generator.