Application of particle tracking velocimetry for studying the dispersion of particles in a turbulent gas flow

A method for the determination of the dispersion of solid particles in a turbulent gas flow has been presented. This method is based on recording the particle trajectories with a high-speed video camera on separate regions of a flow, located at various distances from a point source of particles, and the subsequent processing of the frames. This method has been used to study the dispersion of solid particles under the conditions of turbulence in a horizontal channel with a rectangular cross section of $200\times400$ mm for a measuring region length of $2$ m. Turbulence of the gas flow was generated by means of a grid with square meshes of the size of $16$ mm. The average velocity of the gas flow in the measuring region was $5.1$ m/s. The dispersion of $36$-, $56$- and $128$-micron glass particles of spherical shape was studied in a region $450$ mm long from the point source of particles. It has been shown that the dispersion of these particles in the direction of the action of the gravity force is larger than their dispersion in the perpendicular direction to the gravity force. The results of this study have shown that an increase in the size of particles leads to a decrease in the dispersion at small flight times of the particles (short-time dispersion).