论文标题
飞机POISEUILLE流中复合滴的流体动力学
Hydrodynamics of a Compound Drop in Plane Poiseuille Flow
论文作者
论文摘要
我们从数字上研究了在Stokes制度下平面Poiseuille流中化合物滴的流体动力学。中性浮力的最初同心化合物滴被释放到完全发达的流中，在那里它迁移到其平衡位置。根据结果，我们发现核心壳相互作用会影响核心和化合物滴的动力学。在最初的瞬态期间，由于壳内部循环，核心围绕化合物滴的中心旋转。在平衡下，根据壳体内部的流场的性质，我们确定了两个不同的核心行为：稳定状态和极限周期状态。在稳定状态下，核心停止旋转并非常缓慢地向外移动。极限周期状态中的核心继续在几乎固定的轨道上旋转而没有进一步的内部运动。我们还发现，化合物滴的迁移会显着影响核心的偏心率。与简单滴的比较表明，核心增强了化合物滴的变形。稳定状态下的向外移动芯将化合物滴推向墙壁，并且以极限周期状态的旋转核心使化合物下降到其平衡位置振荡。从参数研究中，我们发现核心仅在中间大小上影响化合物滴动力学，并增加任何参数会导致从极限周期状态到稳定状态的过渡。
We numerically investigate the hydrodynamics of a compound drop in a plane Poiseuille flow under Stokes regime. A neutrally buoyant, initially concentric compound drop is released into a fully developed flow, where it migrates to its equilibrium position. Based on the results, we find that the core-shell interaction affects the dynamics of both the core and the compound drop. During the initial transient period, the core revolves about the center of the compound drop due to the internal circulation inside the shell. At equilibrium, depending upon the nature of the flow field inside the shell, we identify two distinct core behaviors: stable state and limit-cycle state. In the stable state, the core stops revolving and moves outward very slowly. The core in the limit-cycle state continues to revolve in a nearly fixed orbit with no further inward motion. We also find that the migration of the compound drop affects the eccentricity of the core significantly. A comparison with the simple drop reveals that the core enhances the deformation of the compound drop. The outward moving core in stable state pushes the compound drop towards the walls, and the revolving core in limit-cycle state makes the compound drop to oscillate at its equilibrium position. From the parametric study, we find that the core affects the compound drop dynamics only at intermediate sizes, and increase in any parameter sufficiently causes a transition from limit-cycle state to stable state.
