Effect of disturbing flow ring on hydrodynamic cavitation characteristics of self-excited oscillating cavitation used for RB degradation

Abstract

This study developed an innovative structure known as the Disturbed flow Self-excited oscillating cavitator (DF-SEOC) to enhance cavitation performance and improve wastewater treatment efficiency. The DF-SEOC holds a distinct advantage due to its internal disturbing flow ring structure, which effectively blocks the fluid and enhances its performance. This unique design promotes multiple collisions within the cavitator, thereby significantly increasing the cavitation area. To optimize the DF-SEOC's performance, investigations into vapor volume fraction and negative pressure under different structural parameters were conducted to determine the optimal configuration. To achieve this optimization, an integration method combining computational fluid dynamics, surrogate modeling, Non-dominated Sorted Genetic Algorithm-II with Elite Strategies, and gray theory was proposed to search for the Pareto frontier solution. This comprehensive approach enabled the identification of optimal parameters for the DF-SEOC. Furthermore, the proposed optimization scheme was validated through simulation analysis and Rhodamine B degradation experiments, with a comparison against existing cavitators. The simulation results demonstrated that the optimized values of vapor volume fraction and negative pressure for the DF-SEOC increased by 9.71% and 1.71%, respectively, compared to existing cavitators. Additionally, the degradation experiments revealed that the DF-SEOC exhibited a 61.42% higher degradation capacity than existing cavitators.