Particle-laden upward jet in a crossflow: particle dispersion and tracking of particle source*

We experimentally investigate the particle dispersion due to the vortical interaction in the particle-laden upward jet with a crossflow focusing on a large scale phenomena in multiple planes. We vary the velocity ratio (R) between the jet and crossflow, which is classified into three regimes of no crossflow, 3.0 -- 3.5 and 1.0 -- 1.2. As a dispersed phase, we use Silicon particles (6 -- 205 um in size) and the corresponding Stokes number is in the range of St $=$ 0.01 -- 27.42. For each case, the air flow and particle velocities are measured by PIV, and the particle distribution is obtained by planar nephelometry. For lower R, due to stronger counter-rotating vortex pairs (CVPs) in a continuous phase, drag force on particles become dominant so that the particles are swept from the jet center near the jet exit for St \textless \textless 1, but for St \textgreater \textgreater 1, the particles tend to travel along the jet center regardless of vortical effects. Interestingly, only for St $=$ 1 (irrespective of R), the particles agglomerate along the jet center before the CVP collapses. Finally, based on these observations, a 3D dispersion model is developed, which is used for the estimation of particle source location and validated with the experimental data.