Mixing by gas injection is an operation used in industrial processes such as wastewater treatment, metallurgy, or methanization in which pressurized gas is injected into a fluid in order to reduce concentrations and temperatures gradients. This study demonstrates how the CFD toolbox OpenFOAM can be used to simulate such flows. Experimental measurements and observations have been performed on a pilot-scale reactor where pressurized air is injected in a yield stress fluid. The volume of fluid method and an adaptive mesh with refinement at the interface have been used to track the gas inclusions. The numerical model accuracy has been assessed by comparing experimental and numerical results related to the bubble's frequency, dimensions, and rising velocities as well as the fluid recirculation, yielded, and unyielded regions in the tank. The influence of injection parameters such as the injection flow rate and the fluid rheological parameters has been quantified.

中文翻译：

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使用 OpenFOAM 软件在屈服应力流体中通过空气注入进行混合的实验研究和数值模拟

通过气体注入进行混合是工业过程中使用的一种操作，例如废水处理、冶金或甲烷化，其中将加压气体注入流体中以降低浓度和温度梯度。本研究展示了如何使用 CFD 工具箱 OpenFOAM 来模拟此类流动。已经在中试规模的反应器上进行了实验测量和观察，其中将加压空气注入屈服应力流体中。流体体积法和界面细化的自适应网格已用于跟踪气体包裹体。通过比较与气泡的频率、尺寸和上升速度以及储罐中的流体再循环、屈服和未屈服区域相关的实验和数值结果，评估了数值模型的准确性。