The breakup dynamics of bubbles stabilized by nanoparticles in a microfluidic Y-junction

Bubble breakup and boiling heat transfer in Y‐shaped bifurcating microchannels

“…For small acute‐angle bifurcating microchannel ( α = 15°), it is found that the bubble mainly experiences the pre‐breakup and squeezing stages. The pinch‐off stage of bubble breakup is inconspicuous, which is different from some previous studies 12,52–54 . Two possible reasons for this interesting phenomenon are: (1) The bifurcating angle in the present study is relatively small.…”

“…In this stage, one side of the bubble is confined by the windward wall, and the other side of the bubble is directly impacted by upstream fluid. It is observed that the thinning rate of the bubble neck tends to slightly decrease, which is in accord with the experimental study from Fei et al 12 ; (3) Pinch‐off stage, defined as the period between the emergence of pinch‐off behavior and the bubble just breaking. This stage is characterized by the sudden acceleration of the diminishing rate of bubble neck thickness, where the surface tension plays a crucial role and this process is considered to be irreversible 11,53 …”

“…The pinch-off stage of bubble breakup is inconspicuous, which is different from some previous studies. 12,[52][53][54] As can be seen, the increase in heat flux significantly facilitates the bubble growth, while the influence mechanism of the bifurcating angle on bubble growth is relatively complex. The terminal bubble volume in the obtuse bifurcating microchannel (α = 135 ) is larger than that in the small acute-angle bifurcating microchannel (α = 15 ).…”

“…Considerable efforts have been devoted to revealing the bubble/droplet dynamics in the adiabatic Y-shaped bifurcating microchannels, where the breakup stage and flow pattern were recognized as the essential respects. [11][12][13] Xu et al 14 focused on the partially obstructed breakup phenomenon in Y-shaped bifurcating microchannels with various bifurcating angles, bubble lengths, and capillary numbers. Using the high-speed photography, the profiles and evolutions of bubble interface were quantitatively analyzed.…”

“…Unlike the T‐shaped microchannels with the constant bifurcating angle of 180°, the Y‐shaped microchannels have diverse bifurcating angles, 9,10 indicating more complex physical phenomena. Considerable efforts have been devoted to revealing the bubble/droplet dynamics in the adiabatic Y‐shaped bifurcating microchannels, where the breakup stage and flow pattern were recognized as the essential respects 11–13 . Xu et al 14 focused on the partially obstructed breakup phenomenon in Y‐shaped bifurcating microchannels with various bifurcating angles, bubble lengths, and capillary numbers.…”