The characteristics of the near field of the granular jet

This paper investigates the characteristics of the near field of the granular jet (e.g., diameter of granular jet core dc, width of dispersed jet d, and thickness of boundary layer δ). Through image analysis, we find that particle superficial velocity has an important influence on those characteristics. In addition, d and δ linearly grow with the distance from the nozzle exit at first and then remain constant; this phenomenon differs from that in a single-phase jet. The vertical velocity field of the two sides of the jet core is directly obtained by particle image velocimetry. The calculation results suggest that the velocity profile of the boundary layer near the nozzle exit is a parabolic distribution.