Hendrik Reese
Dr. rer. nat. Hendrik Reese
Physik Weicher Materie
Projekt:
Microscopic pumping of viscous liquids by single cavitation bubbles
This cavitation bubble (blue) in water (red) was simulated using OpenFOAM.
Compressibility and viscosity of the fluids is modeled.
On the right half of each frame the velocity field is shown.
It is initiated at a distance of 400 μm from a deformable solid wall (bottom of each frame, thickness: 50 μm, elasticity modulus: 20 MPa) at a high pressure.
It expands and moves towards the wall before collapsing.
During the collapse the bubble pierces itself by creating a high velocity liquid jet directed towards the wall.
As the jet impacts on the wall, it imposes high pressure and shear stress onto the elastic wall and thus deforms it.
The deformation aswell as the shear stress (right side of each frame) at the fluid-solid-interface is shown.
These strong forces onto solid walls created by cavitation bubbles can erode ship propellers and clean surfaces in ultrasonic baths.