Degree Type

Thesis

Date of Award

2013

Degree Name

Master of Science

Department

Electrical and Computer Engineering

First Advisor

Bigelow Timothy

Abstract

The inertial cavitation of bubble clouds has been considered to be the hidden crucial mechanism for recent new therapeutic ultrasound applications such as Histotripsy and the ultrasound drug delivery. Although many models are already put forward to simulate the cavitation process, due to the inaccessible experimental validation, which model works closest to the real world situation is not well investigated. The objective of this thesis is mainly to compare the simulation performance of the popular Rayleigh-Plesset model and Gilmore-Akulichev model exposed to high intensity focused ultrasound in terms of the bubble equilibrium radius, the ultrasonic pressure, frequency and gas diffusion.

Our results show that under the same acoustic wave, before the first collapse, the bubble oscillates similarly with Rayleigh-Plesset and Gilmore-AKulichev models, but it collapses much more violently with Rayleigh-Plesset model. When more cycles of ultrasonic wave are exposed to the bubble, these two models behave disparately both in the oscillation and collapse stages. With Gilmore-Akulichev model, the bubble tends to oscillate in a more stable and bounded shape while it's expands and collapses unrealistically with Rayleigh-Plesset model. Also, the effect of the bubble gas diffusion is explored with Gilmore-Akulichev model. The gas diffusion is found to make the bubble expansion larger and collapse more dramatic, and this ability to sharpen curves tends to be stronger with higher pressure amplitude and lower frequency waves. Finally, GPU CUDA is implemented to simulate the bubble cloud dynamics in Histotripsy via Gilmore-Akuchev model with gas diffusion taken into account. Compared to traditional CPU copulation, our CUDA simulation is proved to be 10X faster.

Copyright Owner

Zhong Hu

Language

en

File Format

application/pdf

File Size

43 pages

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