Dynamic characteristics comparison between non-spherical hydrodynamic cavitation bubbles and spark-induced cavitation...

Area of Science:

• Fluid Dynamics
• Hydrodynamics
• Cavitation Physics

Background:

• Cavitation bubbles are crucial in various scientific and engineering fields.
• Understanding bubble dynamics, especially non-spherical types, is essential for applications.
• Existing methods often struggle to generate stable, single non-spherical cavitation bubbles.

Purpose of the Study:

• To develop a new experimental method for generating single non-spherical hydrodynamic cavitation bubbles.
• To systematically compare the dynamic characteristics of whipping-induced and spark-induced cavitation bubbles.
• To investigate the influence of environmental factors on bubble evolution.

Main Methods:

• Utilizing the whipping motion of a large-deformation flexible body in water to induce cavitation.
• Systematic comparison of bubble evolution, surface morphology, and collapse behavior.
• Analysis of shock wave emission and non-condensable gas content.

Main Results:

• Stable generation of single non-spherical cavitation bubbles achieved via whipping motion.
• Whipping-induced bubbles exhibit rough surfaces, daughter bubble shedding, and temporal asymmetry.
• Spark-induced bubbles evolve spherically with smooth surfaces and symmetric growth/collapse.
• Whipping-induced bubbles produce multi-sequential shock waves; spark-induced bubbles emit isolated, high-pressure shock waves.
• Lower non-condensable gas content in whipping-induced bubbles leads to shorter lifetimes.

Conclusions:

• The whipping motion method provides a novel approach for studying non-spherical hydrodynamic cavitation bubbles.
• Significant differences in dynamic characteristics and shock wave generation exist between whipping-induced and spark-induced bubbles.
• This study lays a foundation for understanding the applicability of non-spherical bubbles in research.