Investigation of turbulence modification by PIV tracer particles in a supersonic mixing layer

The turbulence modification by Particle Image Velocimetry (PIV) tracer particles was investigated with the two-way coupling of 2D spatial development supersonic gas-solid two-phase mixing layer. The gas phase coupled with the dispersion phase were simulated by the large eddy simulation and the Lagrangian trajectory model, respectively. It is found that the streamwise turbulence of the mixing layer is weakened, the transverse turbulence of the mixing layer strengthened and the Reynolds stress peak value increased by 9.68% than that of the unladen mixing layer due to the small Stokes particles. However, the root mean square velocity of the mixing layer is weakened by the large Stokes particles, and the Reynolds stress peak value is only 41.74% of that of the unladen mixing layer. The root mean square transverse velocity with the large mass loading is 38.63% of that of unladen mixing layer, and it is partly counteracted by the motion of particles. The root mean square transverse velocity and the Reynolds stress with the middle mass loading are almost equal to those of the unladen mixing layer. The largest root mean square streamwise velocity is reduced by 19.29% whereas the root mean square transverse velocity near the centerline of the mixing layer is increased by the small mass loading. The modification to the turbulence of the supersonic mixing layer under the small Stokes number and middle mass loading condition is smaller than other cases. The study provides important reference for improving PIV experiment in high speed flows.