Combined of liquid temperature and wall on the cavitation bubble prolongation effect

The dynamic behavior of a near-wall bubble is strongly governed by the bubble-wall distance, and the addition of liquid temperature effects further complicates this process. Using an underwater Corona single-electrode discharge to induce a bubble and a temperature control system, this study investigates the prolongation effect of a bubble near a rigid wall at liquid temperatures of 10-90 °C and dimensionless bubble-wall distances of 0.6-1.8. The experimental results indicate the existence of a critical temperature (≈53 °C). When temperature is below it, expansion time of bubble is longer than collapse time; when temperature is above it, collapse time is longer than expansion time. Statistical analysis reveals that at the same temperature, when the dimensionless bubble-wall distance is less than 1, a third-order polynomial fits the experimental data well (10-80 °C); when it is greater than 1, a second-order polynomial is sufficient to satisfy the experimental accuracy (10-80 °C). By considering the combined effects of the wall and liquid temperature, this study summarizes an empirical method for the bubble prolongation factor as a function of the dimensionless bubble-wall distance and liquid temperature for the Corona discharge method, which can be used to evaluate bubble evolution characteristics.