Regulation of velocity zoning behaviour and hydraulic jump of impinging jet flow on a spinning disk reactor

A spinning disk reactor is a promising contacting device used in the synthesis of nanoparticles through reactive precipitation. The synthesis performance depends on the flow characteristics of the liquid film on the reactor. Using a glycerol–water solution as the experimental medium, this study examined the three distinct zones of the radial velocity profile and the formation of hydraulic jump through laser Doppler velocimetry and volume-of-fluid methods. The results showed that as the inlet Reynolds number increases, the inertial effect dominates farther out and pushes the three zones outwards, a wider acceleration zone is obtained, and the pouring diameter does not affect the synchronisation zone. At higher rotational speeds, the centrifugal effect dominates even at a smaller radius, and the three zones move inwards, leading to a wider synchronisation zone. The hydraulic jump generally occurs at lower rotational speeds, higher viscosity, or smaller pouring diameter. At higher inlet Reynolds number or lower speeds, the jump region expands and migrates outwards. Although the pouring diameter can determine whether the jump occurs, it only slightly affects the location of the jump. The synchronisation and jump radii can be predicted using the radial length scale factor. The Nusselt model was modified by incorporating a correction term, and a regression model was proposed to predict the maximum film height.