A computational technique was developed to simulate wettable particles trapped at a fluid-fluid interface under gravity. The proposed technique combines the improved smoothed profile-lattice Boltzmann method (iSP-LBM) for the treatment of moving solid-fluid boundaries and the free-energy LBM for the description of isodensity immiscible two-phase flows. We considered five benchmark problems in two-dimensional systems, including a stationary drop, a wettable particle trapped at a fluid-fluid interface in the absence or presence of gravity, two freely moving particles at a fluid-fluid interface in the presence of gravity (i.e., capillary floatation forces), and two vertically constrained particles at a fluid-fluid interface (i.e., capillary immersion forces). The simulation results agreed well with theoretical estimations, demonstrating the efficacy of the proposed technique.

中文翻译：

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用于重力作用下流体-流体界面可湿性颗粒模拟的格子玻尔兹曼方法

开发了一种计算技术来模拟重力作用下捕获在流体-流体界面的可湿性颗粒。拟议的技术结合了改进的平滑轮廓格子玻尔兹曼方法（iSP-LBM）来处理固相流动边界，而自由能LBM则用于描述等密度不混溶两相流。我们考虑了二维系统中的五个基准问题，包括固定液滴，在不存在或存在重力的情况下被困在流体-流体界面的可润湿颗粒，在存在重力的情况下在流体-流体界面的两个自由移动的颗粒（ （即毛细作用力）和两个在流体-流体界面处垂直约束的颗粒（即毛细作用力）。仿真结果与理论估计吻合得很好，