Abstract

In this study, a programmed code written in MATLAB was used to numerically solve the Rayleigh-Plesset Equation (RPE), Modified Rayleigh-Plesset Equation (MRPE), and Keller-Miksis Equation (KME). A solver in OpenFOAMextend was modified and used to simulate multiphase flow dynamics and investigate bubble behavior. Numerical simulations were conducted using the Finite Volume Method combined with the Volume of Fluid Method in OpenFOAMextend. ParaView was used to visualize the flow fields. The dissertation first simulates a single gas bubble oscillating in an unbounded liquid, validating results against Rayleigh-Plesset equation solutions. Subsequently, it investigates a laser-induced bubble confined between two parallel rigid walls, examining the effects of confinement and off-centre distance on bubble dynamics. Results show that bubble location and confinement degree significantly influence liquid jet strength and wall pressures, with increasing confinement leading to decreased peak pressures and velocities at the walls. The study further explores an ultrasonically driven gas bubble situated between parallel rigid circular walls with a cylindrical micro-indentation. This investigation aims to determine conditions facilitating particulate contamination removal using the bubble’s liquid jet. Results indicate that effective contamination removal occurs when the dimensionless indentation diameter (D*) is less than 4, with the bubble splitting into two sub-bubbles during collapse for D* < 4.9. For larger indentation diameters, the lower sub-bubble vanishes, preventing contamination removal. This dissertation provides new insights into the complex dynamics of confined, laser-induced cavitation bubbles and ultrasonically driven gas bubbles. The findings have significant implications for various engineering applications, including medical ultrasound therapies, industrial cleaning processes, and sonochemistry, where precise control over bubble dynamics is crucial. This study offers valuable tools for achieving such control in these fields.