In part 1 (V. S. Dharodi and A. Das, J. Plasma Phys. 87 (02), 905870216 (2021)), we simulated the individual dynamics of a bubble (a localized low-density region) and a droplet (a localized high-density region) in a strongly coupled dusty plasma. We observed that under the influence of gravity, the result of a pair of counter-rotating vorticity lobes causes the bubble to rise and droplet to fall. With an interest to understand the hetero- (bubble–droplet) interactions between them, we extend this study to their combined evolution through the following two arrangements. First, both are placed side-by-side in a row at the same height. We observe that the overall dynamics is governed by the competition between the net vertical motion induced by gravity and rotational motion induced by the pairing between two co-rotating inner vorticity lobes. In the second arrangement, the vertically aligned bubble (below) and droplet (above) after collision exchange their partners and subsequently start to move horizontally in opposite directions away from each other. This horizontal movement becomes slower with increasing coupling strength. For these arrangements, we consider varying the distance between the fixed-size bubble and droplet, and varying the coupling strength. To visualize the bubble–droplet interactions, a series of two-dimensional simulations have been conducted in the framework of an incompressible generalized hydrodynamic viscoelastic fluid model.

中文翻译：

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强耦合尘埃等离子体中重力驱动不稳定性的数值研究。第 2 部分。上升气泡和下降液滴之间的异质相互作用

在第 1 部分（VS Dharodi 和 A. Das, J. Plasma Phys. 87 (02), 905870216 (2021)）中，我们模拟了气泡（局部低密度区域）和液滴（局部高-密度区域）在强耦合的尘埃等离子体中。我们观察到，在重力的影响下，一对反向旋转的涡量叶片的结果导致气泡上升，液滴下降。为了了解它们之间的异质（气泡 - 液滴）相互作用，我们通过以下两种安排将这项研究扩展到它们的组合进化。首先，两者并排放置在同一高度的一排。我们观察到整体动力学由重力引起的净垂直运动和两个同向旋转的内涡旋叶之间的配对引起的旋转运动之间的竞争控制。在第二种排列中，垂直排列的气泡（下）和液滴（上）在碰撞后交换它们的伙伴，随后开始在相反方向上水平移动，远离彼此。这种水平运动随着耦合强度的增加而变慢。对于这些布置，我们考虑改变固定大小的气泡和液滴之间的距离，并改变耦合强度。为了可视化气泡-液滴相互作用，已经在不可压缩广义流体动力粘弹性流体模型的框架下进行了一系列二维模拟。这种水平运动随着耦合强度的增加而变慢。对于这些布置，我们考虑改变固定大小的气泡和液滴之间的距离，并改变耦合强度。为了可视化气泡-液滴相互作用，已经在不可压缩广义流体动力粘弹性流体模型的框架下进行了一系列二维模拟。这种水平运动随着耦合强度的增加而变慢。对于这些布置，我们考虑改变固定大小的气泡和液滴之间的距离，并改变耦合强度。为了可视化气泡-液滴相互作用，已经在不可压缩广义流体动力粘弹性流体模型的框架下进行了一系列二维模拟。