Dripping-Jetting Transitions in a Dripping Faucet

Abstract

Fascinating dynamics is known to result when the flow rate Q at which water drips from a faucet varies. Starting with simple (period-1) dripping, the system transitions as Q increases to complex dripping, where it exhibits period-n (n=2,4, em leader ) and chaotic responses, and then jets once Q exceeds a threshold. New experiments and simulations show that high viscosity (micro) liquids, e.g., syrup, transition directly from simple dripping to jetting as Q increases. Phase diagrams showing transitions between simple and complex dripping and jetting in (Q,micro) space are developed. Values of Q for transition from dripping to jetting are estimated from scaling arguments and shown to accord well with simulations.

Universal Dripping and Jetting in a Transverse Shear Flow

“…See Table I for symbol definitions. varies in We-Oh DP space at low Ca, and again we find remarkable similarity to what has been observed in the dripping faucet geometry [19].…”

“…(5), is adapted from Refs. [19,20]. Jetting can also be observed below this surface if the predicted droplet size is D=D 0 < 2 (not shown).…”

“…3(a) and 3(c). Similarly, Ambravaneswaran et al generated a phase diagram in We-Oh DP space at fixed Bo through numerical simulations [19]; their data are reasonably well described by a twosegment piecewise power law in Oh DP (corresponding to the inviscid and finite DP limits). Again, this expression describes our data when Oh DP is rescaled; the solid line in Fig.…”

“…We define jetting as occurring when the length of the neck L n at snap-off exceeds the droplet diameter: L n =D > 1, which correlates with large changes in D=D 0 over the range of Ca studied. A similar criterion is used in the dripping faucet literature [19]. At sufficiently low We and Ca, dripping is always observed, and, as either is increased, the behavior will eventually transition to jetting.…”

Insulated multinozzle system for electrohydrodynamic atomization in the simple-jet mode

“…Recently, Agostinho et al 8 have related the electrospray modes with the different regimes used in non-charged situations to classify the formation of the droplets, i.e., dripping regime, jetting regime, and transition regime. [9][10][11] The authors said that the electrospraying modes known as dripping, microdripping, spindle, intermittent cone-jet, and cone-jet mode happen when the flow is adjusted to a level comparable to the dripping regime (low flow rates) and the simple-jet mode happens when the flow rate is adjusted to a level comparable to the transition and jetting regimes (higher flow rates).…”