Study on the mesoscale causes of the influence of surface tension on material erosion in a cavitation field

ABSTRACT

Cavitation erosion is a fundamental concern in many fields of engineering, e.g. the flow separation zone in high speed flow and the blade area of hydraulic machinery. However, the influence of the physical characteristics of the environmental medium in these engineering facilities on cavitation erosion is still unclear. In this paper, we adopted underwater low-voltage discharge technology to generate cavitation bubbles, and studied the mesoscale causes of material erosion in solutions with different surface tensions. It is found that with the decrease of liquid surface tension, the radial velocity of cavitation bubbles decreases significantly during the shrinkage of the cavitation bubble and the minimum radius to which the cavitation bubble shrinks increases, the micro-jet generated by the cavitation bubble develops more slowly, and the impact strength of cavitation bubble collapses on the wall decreases. The findings reveal new physical mechanisms of the cavitation-induced material erosion in liquids with different surface tensions at the macroscopic level. These will provide significant guidance for cavitation prevention in various applications such as aeration cavitation-alleviation, hydraulic machinery, ultrasonic cleaning and the medical industry.

Keywords:

• Bubble dynamics
• cavitation erosion
• impact strength
• liquid jet
• surface tension

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [Grant 51879178], the Open Research Funding [SKHL1710] and [SKHL1712] from the State Key Laboratory of Hydraulics and Mountain River Engineering in Sichuan University.