Faculty of Mechanical Engineering, University of Ljubljana, Askerčeva 6, 1000 Ljubljana, Slovenia.
Institut Lumière Matière, Université Claude Bernard Lyon 1, 69622 Villeurbanne, France.
Water Res. 2022 Jul 15;220:118628. doi: 10.1016/j.watres.2022.118628. Epub 2022 May 17.
Hydrodynamic cavitation was evaluated for its reactive oxygen species production in several convergent-divergent microchannel at the transition from micro to milli scale. Channel widths and heights were systematically varied to study the influence of geometrical parameters at the transitory scale. A photomultiplier tube was used for time-resolved photon detection and monitoring of the chemiluminescent luminol oxidation reactions, allowing for a contactless and in situ quantization of reactive oxygen species production in the channels. The radical production rates at various flow parameters were evaluated, showing an optimal yield per flow rate exists in the observed geometrical range. While cavitation cloud shedding was the prevailing regime in this type of channels, the photon arrival time analysis allowed for an investigation of the cavitation structure dynamics and their contribution to the chemical yield, revealing that radical production is not linked to the synchronous cavitation cloud collapse events. Instead, individual bubble collapses occurring throughout the cloud formation were recognized to be the source of the reactive oxygen species.
在从微尺度到毫尺度的转变过程中，评估了在几个会聚-发散微通道中水力空化对活性氧物质生成的作用。系统地改变通道的宽度和高度，以研究过渡尺度上几何参数的影响。光电倍增管用于时间分辨光子检测和监测化学发光鲁米诺氧化反应，实现了通道内活性氧物质生成的非接触式和原位定量。在各种流动参数下评估了自由基生成速率，结果表明在观察到的几何范围内存在每流速的最佳产率。虽然在这种类型的通道中，空化云的脱落是主要的状态，但光子到达时间分析允许研究空化结构动力学及其对化学产率的贡献，结果表明自由基的产生与同步空化云崩溃事件无关。相反，识别到整个云形成过程中单个气泡的崩溃是活性氧物质的来源。
