Laboratoire Matière et Systèmes Complexes

November 2nd 11h30

There will be a live diffusion with Zoom.
Contact Michael Berhanu to attend the video seminar.

Adrien Bussonnière, Chargé de recherche CNRS

Laboratoire Matière et Systèmes Complexes (MSC), Université de Paris.

Regeneration of cavitation nuclei

Bubbles apparition in soda drink, during boiling or by reducing the pressure, i.e., cavitation events, are known to arise from much smaller bubbles, called nuclei, trapped by impurities in liquid or defects on the walls. These nuclei are usually assumed to be trapped in defects during the filling of containers or when impurities enter in the liquid. Their sizes and numbers are therefore challenging to control and cavitation events remain difficult to predict/control. To further explore the origin of such nuclei, we focalized several short acoustic pulses into a suspension of micro-sized particles, a method known to deplete the nuclei. The cavitation is monitored over the entire experiment by measuring the cavitation probability. Surprisingly, a stable cavitation probability emerges after a few thousand impulsions indicating a stable nuclei population. By varying the excitation, we show that this peculiar regime arises from a balance between the acoustic depletion and an unexpected spontaneous nuclei regeneration. Finally, a simple model is developed to get insights into this nuclei reformation.