Particulate flows in a mixture of gas and liquid, i.e. gas–liquid–solid three-phase flows, are frequently encountered both in nature and industry. In such flows, complex interactions between multiple phases, i.e. particle–particle interactions, fluid–particle interactions and interfacial interactions (such as surface tension and particle wetting), play a crucial role. In literature, simulations of three-phase flows are sometimes performed by incorporating interface capturing methods (e.g. VOF method) into the CFD–DEM coupling model. However, it is practically impossible to perform large (industrial) scale simulation because of the high computational cost. One of the strategies often employed to reduce the computational cost in CFD–DEM is to upscale particle size, which is applied mainly to particle single-phase and fluid–solid two-phase flows. The present work is focused on the scaled-up particle model for gas–liquid–solid three-phase flows. The interaction forces between multiple phases are scaled using the general criteria derived from the continuum assumption of particulate flow. A colour function based interface-capturing method with improved interface smoothness is developed, and the diffusion based coarse graining is employed to ensure sufficient space resolution in CFD even when particle size is increased. It is shown that the model developed is capable of predicting the both particles and fluid behaviour in the original system.

气体和液体混合物中的颗粒流，即气-液-固三相流，在自然界和工业界都经常遇到。在这样的流动中，多个相之间的复杂相互作用，即颗粒间相互作用，流体间相互作用和界面相互作用（例如表面张力和颗粒润湿）起着至关重要的作用。在文献中，有时会通过将接口捕获方法（例如VOF方法）合并到CFD-DEM耦合模型中来进行三相流的仿真。但是，由于计算成本高，因此实际上不可能执行大型（工业）仿真。降低CFD-DEM中计算成本的常用策略之一是提高粒径，这主要应用于颗粒单相和流固两相流。目前的工作集中于气-液-固三相流的放大粒子模型。多相之间的相互作用力使用从微粒流动的连续假设得出的一般标准进行缩放。开发了具有改进的界面光滑度的基于颜色函数的界面捕获方法，并且采用了基于扩散的粗粒度以确保CFD中足够的空间分辨率，即使在增大粒径时也是如此。结果表明，所开发的模型能够预测原始系统中的颗粒和流体行为。开发了具有改善的界面光滑度的基于颜色函数的界面捕获方法，并且采用了基于扩散的粗粒度以确保CFD中足够的空间分辨率，即使增加了粒径。结果表明，所开发的模型能够预测原始系统中的颗粒和流体行为。开发了具有改善的界面光滑度的基于颜色函数的界面捕获方法，并且采用了基于扩散的粗粒度以确保CFD中足够的空间分辨率，即使增加了粒径。结果表明，所开发的模型能够预测原始系统中的颗粒和流体行为。