| Popis: |
The ultrasound-induced growth and collapse of a bubble results from the oscillating position of an ultrasound transducer face in a liquid medium. The current work presents a fully-compressible model that is the first to capture the growth and collapse of a bubble set in a liquid medium subjected to an ultrasound transducer. The oscillating transducer face is represented by an immersed moving reflective boundary. The flow is simulated using a conservative interface capturing method, which includes the use of a high-order WENO reconstruction, a maximum-principle-satisfying and positivity-preserving limiter, and the HLLC approximate Riemann flux. A simulation is conducted of the growth and collapse of an initially spherical bubble with an initial radius of 50 µm near a wall subjected to the acoustic field resulting from a transducer face oscillating with a frequency of 30 kHz and a displacement amplitude of 0.6956 µm. The shape of the bubble during the growth and collapse is found to be qualitatively consistent with previous work, with a flattening of the bubble near the wall after the growth and the formation of a jet during the collapse. The violent collapse of the bubble results in a maximum pressure at the wall of approximately 14 MPa. |
