Direct simulation of multiphase flows with modeling of dynamic interface contact angle
Direct simulation of multiphase flows with modeling of dynamic interface contact angle
复制标题
通过动态界面接触角建模直接模拟多相流
DOI：
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发表时间：
2018
影响因子：
3.4
通讯作者：
D. Juric
中科院分区：
文献类型：
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作者：
Seungwon Shin;J. Chergui;D. Juric
我们描述了一种建模技术的动态接触角之间的相界面和固体壁面使用广义Navier边界条件的背景下，前跟踪为基础的多相方法。接触线的运动由广义Navier滑移边界条件确定，以消除接触线处的无穷大剪应力。与允许流体沿着固体表面完全滑移相比，仅将该滑移边界条件应用于具有各种滑移率的界面运动，显示出与实验结果良好的一致性。界面滑移模型在滑移率和滑移长度模型的网格收敛试验中表现良好。进行了详细的能量分析，以确定动能，表面能和势能以及粘性和接触线耗散随时间的变化。基于计算的其他能量项，获得了接触线耗散的摩擦系数。对不同网格分辨率下的能量项和摩擦系数进行了比较。分析了不同滑移率以及接触角分布对接触线速度的影响。研究了液滴在不同前进角和后退角情况下对固体壁面的撞击行为。最后，将所提出的动态接触模型扩展到三维，以实现大规模并行计算。模拟液滴对固体圆柱体的冲击，以证明所提出的制剂对一般固体结构的能力。广泛不同的接触角进行了测试，并清楚地显示出独特的特征行为。
We describe a modeling technique for dynamic contact angle between a phase interface and a solid wall using a generalized Navier boundary condition in the context of a front-tracking-based multiphase method. The contact line motion is determined by the generalized Navier slip boundary condition in order to eliminate the infinite shear stress at the contact line. Applying this slip boundary condition only to the interface movement with various slip ratios shows good agreement with experimental results compared to allowing full fluid slip along the solid surface. The interface slip model performs well on grid convergence tests using both the slip ratio and slip length models. A detailed energy analysis was performed to identify changes in kinetic, surface, and potential energies as well as viscous and contact line dissipation with time. A friction coefficient for contact line dissipation was obtained based on the other computed energy terms. Each energy term and the friction coefficient were compared for different grid resolutions. The effect of varying the slip ratio as well as the contact angle distribution versus contact line speed was analyzed. The behavior of drop impact on a solid wall with different advancing and receding angles was investigated. Finally, the proposed dynamic contact model was extended to three dimensions for large-scale parallel calculations. The impact of a droplet on a solid cylinder was simulated to demonstrate the capabilities of the proposing formulation on general solid structures. Widely different contact angles were tested and showed distinctive characteristic behavior clearly.