Séminaire de Mécanique d'Orsay

Le Mercredi 18 juin à 14h00 - Salle du Conseil du LIMSI

Interaction between a laminar starting immersed jet and a parallel wall

Guillermo Artana
Fluid Dynamics Laboratory FI UBA Buenos Aires, Argentina

In the present talk we present a study about the starting transient of an immersed micro-jet in close vicinity to a solid wall parallel to its axis. The experiments concern laminar jets (Re < 200) issuing from a 100~um internal tip diameter glass micro-pipette. The effect of the confinement was studied placing the micro-pipette at different distances from the wall. The characterization of the jet was carried out by visualizations on which the morphology of the vortex head and trajectories were analyzed. Numerical simulations were used as a complementary tool for the analysis. The self-similar behavior of the starting jet has been studied in terms of the frontline position with time. A symmetric and a wall dominated regime could be identified. The starting jet in the wall type regime, and in the symmetric regime as well, develops a self-similar behavior that has a relative rapid loss of memory of the preceding condition of the flow. Scaling for both regimes are those that correspond to viscous dominated flows.