Jets, drops and liquid bridges : stretching liquid flows
Orateur : Mariano Rubio-Rubio
Departamento de Ingeniería Térmica y de Fluidos Universidad Carlos III de Madrid, Spain
Résumé :
I. GLOBAL STABILITY OF GRAVITATIONALLY STRETCHED CAPILLARY JETS
Jets, drops and liquid bridges : stretching liquid flows We analyze the global linear stability of capillary jets stretched by gravity both experimentally and theoretically, revealing the essential stabilizing role played by the axial curvature of the jet, specially relevant for injectors with a large diameter. The model accurately predicts the onset of jet self-excited oscillations experimentally observed for wide ranges of liquid viscosity and injector diameter showing better agreement with the experimental jetting-dripping transition events than those available in the literature.
II. DRIPPING FAUCET AT HIGH BOND NUMBERS
We present new experiments on the dripping dynamics and jetting transition for a wide range of both the liquid viscosity and the size of the injector. Our results reveal the existence of new dynamics in the dripping regime not observed at small Bond numbers. In addition, we quantify the hysteresis present in the dripping-jetting transition, previously measured only for the inviscid case.
III. FINAL STAGE PINCHING OF PARTICLE SUPENSION FILAMENTS
To explain the different thinning velocities present near the pinch-off of particle suspensions in a Newtonian matrix, we model the liquid trapped between two end particles as a stretching liquid bridge with a non-uniform prescribed movement of the end plates. Our model, based on the one-dimensional mass and momentum conservation equations, shows good quantitative agreement with the experimental thinning behavior.
Date et lieu : le Vendredi 6 Mars 2015 à 11:00, salle de séminaires IRPHE