Cavitation bubble interaction with a rigid spherical particle on a microscale
1University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva cesta 6, Ljubljana, Slovenia.
Ultrasonics Sonochemistry
|July 19, 2020
Summary
Microscale cavitation bubble collapse near spheres can damage bacteria via shear loads and shock waves. Bubble jetting is less likely at this scale due to surface tension effects, but mechanical loads increase with sphere-bubble size ratio.
Area of Science:
- Fluid Dynamics
- Acoustics
- Biophysics
Background:
- Cavitation bubble collapse generates significant mechanical forces.
- Understanding microscale interactions is crucial for applications like bacterial eradication.
Purpose of the Study:
- Investigate numerically the mechanical effects of microscale cavitation bubble collapse near a submerged sphere.
- Determine the potential for bacterial cell damage from these effects.
Main Methods:
- Finite volume method for numerical simulation.
- Axisymmetric numerical model validated against Gilmore's equation.
- Simulations varied bubble-sphere standoff distance and size ratio.
Main Results:
- Bubble collapse dynamics varied significantly with parameters.
- Bubble jetting was less likely at microscale due to surface tension.
- Mechanical loads increased with sphere-bubble size ratio and decreased with distance.
Conclusions:
- Microscale cavitation can induce shear loads (MPa) and shock waves (hundreds of MPa).
- These loads pose a risk for bacterial cell damage.
- Hydrodynamic cavitation shows potential for bacteria eradication.
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