A new pressure formulation for gas-compressibility dampening in bubble dynamics models

Area of Science:

• Acoustics
• Fluid Dynamics
• Thermodynamics

Background:

• Nonlinear bubble oscillations are crucial in various applications, including ultrasound therapy and industrial processes.
• Existing models often simplify gas pressure dynamics within bubbles, leading to inaccuracies, especially under high-intensity ultrasound.

Purpose of the Study:

• To develop and validate a novel pressure equation for bubbles undergoing nonlinear radial oscillations under high ultrasonic pressure.
• To improve the accuracy of bubble dynamics models by incorporating gas compressibility effects during collapse and rebound.

Main Methods:

• Formulated a new pressure equation accounting for inhomogeneous gas pressure within inertial bubbles.
• Applied the pressure correction to the incompressible Rayleigh-Plesset and compressible Keller and Miksis bubble dynamic models.
• Compared simulation results with experimental data and other compressibility-aware models.

Main Results:

• The proposed inhomogeneous pressure formulation significantly improved predictions of nonlinear bubble radial motion over time.
• Corrected models demonstrated closer agreement with experimental data compared to existing alternative models.
• Enhanced accuracy was observed for both Rayleigh-Plesset and Keller and Miksis equations.

Conclusions:

• The developed inhomogeneous pressure equation enhances the predictive accuracy of bubble dynamics models.
• The Rayleigh-Plesset family of equations benefits significantly from this pressure correction, improving their applicability.
• This work offers a more robust approach to modeling cavitation bubble behavior under ultrasonic conditions.