Liquid film dynamics during meniscus oscillation

Xiaolong Zhang (1, 2, 3) , Vadim S Nikolayev (1, 2, 3)

1 Université Paris-Saclay
2 CEA - CEA- Saclay
3 SPEC - UMR3680 - Service de physique de l'état condensé

To describe the functioning of pulsating heat pipe, one needs to understand the dynamics of evaporation of thin liquid films deposited by the oscillating meniscus inside a heated capillary. Following the theory of Taylor bubbles, the dynamic profile of the liquid-vapor interface is calculated within a 2D numerical approach using the lubrication approximation. First, the steady vicinity of the contact line is analyzed under evaporation for the partial wetting case to find a relation between the microscopic and apparent contact angles. Next, the film evolution driven by the oscillating meniscus with a pinned contact line is discussed under adiabatic conditions. Finally, the evaporation of oscillating film is considered. It is shown that the film oscillation with a pinned contact line is impossible when the capillary superheating exceeds a threshold; the contact line receding needs to be taken into consideration.

Domaines: Physique [physics]; Sciences de l'ingénieur [physics]; Mécanique des fluides [physics.class-ph]

Xiaolong Zhang, Vadim S Nikolayev. Liquid film dynamics during meniscus oscillation. Joint 20th International Heat Pipe Conference and 14th International Heat Pipe Symposium, Sep 2021, Gelendzhik, Russia. ⟨hal-03388046⟩