Swirling-flow nanobubble generator is an efficient hydrodynamic cavitation method that can continuously produce enormous quantities of bulk nanobubbles. However, the development of hydrodynamic models of nanobubble generation remains challenging and is rarely found in the literature due to the associated modeling complexity. In this work, a hydrodynamic model was developed to predict bubble size distribution in a swirling-flow type nanobubble generator using a combination of computational fluid dynamics (CFD) and population balance method (PBM). The proposed model was evaluated by considering several combinations of bubble coalescence, breakage, and turbulence models. The results show that the combination of the turbulence coalescence and Luo breakage models predicted better than any other model combination. The selection of appropriate turbulence models could improve the modeling accuracy. The standard k-Ω model provided better predictions than other turbulence models for high flow rates, while the standard k-ε model was more appropriate for low flow rates. The bubble number density was successfully predicted for a 30 min generation time. The turbulence dissipation rate influenced the bubble number density and mass transfer, and the results of simulation considering this relation corresponded to the experimental results. Therefore, the coupled CFD-PBM model can aid in the design of nanobubble generators using virtual prototypes and reduce the development costs required for broader applications.

旋流纳米气泡发生器是一种高效的流体动力空化方法，可以连续产生大量的块状纳米气泡。然而，纳米气泡产生的流体动力学模型的开发仍然具有挑战性，并且由于相关的建模复杂性而在文献中很少发现。在这项工作中，使用计算流体动力学 (CFD) 和总体平衡方法 (PBM) 的组合，开发了一种流体动力学模型来预测旋流型纳米气泡发生器中的气泡尺寸分布。通过考虑气泡聚结、破裂和湍流模型的几种组合来评估所提出的模型。结果表明，湍流聚结和洛断裂模型的组合比任何其他模型组合的预测效果更好。选择合适的湍流模型可以提高建模精度。对于高流速，标准 k-Ω 模型比其他湍流模型提供更好的预测，而标准 k-ε 模型更适合低流速。成功预测了 30 分钟生成时间的气泡数密度。湍流耗散率影响气泡数密度和传质，考虑这一关系的模拟结果与实验结果一致。因此，耦合 CFD-PBM 模型可以帮助使用虚拟原型设计纳米气泡发生器，并降低更广泛应用所需的开发成本。而标准的 k-ε 模型更适合低流速。成功预测了 30 分钟生成时间的气泡数密度。湍流耗散率影响气泡数密度和传质，考虑这一关系的模拟结果与实验结果一致。因此，耦合 CFD-PBM 模型可以帮助使用虚拟原型设计纳米气泡发生器，并降低更广泛应用所需的开发成本。而标准的 k-ε 模型更适合低流速。成功预测了 30 分钟生成时间的气泡数密度。湍流耗散率影响气泡数密度和传质，考虑这一关系的模拟结果与实验结果一致。因此，耦合 CFD-PBM 模型可以帮助使用虚拟原型设计纳米气泡发生器，并降低更广泛应用所需的开发成本。