Crossover behavior study of a thinning liquid bridge using the dissipative particle dynamics method

- A liquid bridge thinning with a crossover point is simulated.
- Increasing the viscosity facilitates the crossover.
- Interfacial stress fluctuations strength is not a key factor.
- Fluctuation correlation length is the key factor causing the crossover.

In this work, the dissipative particle dynamics method is used to explore the thinning process of a liquid bridge transforming from macroscopic factor domination to thermal fluctuation domination. Both the inertial-force-dominated thinning profile and the thermal-fluctuation-dominated thinning profile are of self-similarity characteristics. Our simulations show that the scaling factors are in accordance with theoretical results. To explore crossover behavior, concentration is on the transitional regime, where both macroscopic factor domination and microscopic factor domination can be observed. The crossover time depends mainly on the stochastic coefficient. With the conservative forces not being considered, the decrease of the stochastic coefficient results in a wider thermal-fluctuation-dominated regime, but the crossover radius remains nearly unchanged. It is found that the increase in viscosity aids in the dominance of the thermal fluctuations and the emergence of the double-cone breakup profile. Surface stress fluctuations and bulk density fluctuations are examined to investigate the origin of the crossover. The results of these simulations suggest that the key factor of the crossover is the fluctuation correlation length, rather than the strength of the interfacial stress fluctuations. The simulation results also support the conclusion of previous researchers who have determined that it is the balance between the driving capillary pressure and the thermal energy density in the neck that causes crossover.