Impact of Newtonian Liquid Jets on Smooth and Patterned Solid Walls

Immersed jets impact on smooth and patterned solid surfaces was investigated experimentally. The same fluid was used for the jet and as the surrounding fluid. The analyzed flow is in the laminar domain. Six different cases were analyzed, depending on the needle inner diameter, the distance between the nozzle and the walls, the imposed flow rate and the geometrical characteristics of the plates. The study focused on the jet evolution and on the jet impact with the walls. The results were examined in order to determine the influence of the pattern type upon the location of the detachment / separation point of the boundary layer of the vortex ring. The visualizations also show the qualitative modifications in the flow spectrum. This work provides important information for developing new applications related to cooling technology for heat dissipation, microfluidics field and bioengineering.