Study on high‐viscosity bubble breakup dynamics in Y‐shaped microchannel integrating sudden contraction and Murray's law

Micro‐reaction technology introduces bubbles to intensify mixing in high‐viscosity systems, but traditional distributors lack sufficient squeezing and shearing forces. Consequently, designing novel microchannel structures is needed. This study proposes a Y‐shaped microchannel integrating Murray's law and sudden contraction structures, investigating bubble breakup dynamics in high‐viscosity continuous phases. Results show Murray's law channels ensure stable flow distribution, while sudden contraction structures stretch bubbles past critical dimensionless length ( l crit / W m ≈1.40). Their synergy broadens the operating boundary, achieving highly symmetric and monodisperse bubble distribution. Kinetic analysis reveals high viscosity causes intense viscous dissipation, retarding neck film drainage and suppressing final‐stage breakup instability. As the Ohnesorge number increases, the breakup mechanism transitions from inertia‐dominated to viscosity‐dominated. A semi‐empirical prediction model for bubble size was established, incorporating gas–liquid flow rate ratio, Capillary, and Ohnesorge numbers (error within ±15%), providing a theoretical basis for numbering‐up high‐viscosity multiphase micro‐chemical systems.