等直径微液滴碰撞过程的改进光滑粒子动力学模拟
Numerical study of collision process between two equal diameter liquid micro-droplets using a modified smoothed particle hydrodynamics method
-
摘要: 运用一种改进光滑粒子动力学(SPH)方法模拟了相溶和不相溶两种情况下的等直径微液滴碰撞动力学过程。为提高传统SPH方法的数值精度和稳定性,采用一种不涉及核导数计算的核梯度改进形式;为处理液滴界面张力采用修正的van der Waals表面张力模型。通过模拟牛顿液滴碰撞聚并变形过程并与相关文献或试验结果进行对比,验证了改进SPH方法模拟微液滴碰撞过程的可靠性。随后,研究了基于van der Waals模型相溶聚合物微液滴碰撞聚并变形过程及不相溶微液滴碰撞后的反弹、分离过程,讨论了碰撞过程中碰撞速度、碰撞角度、密度比等参数对碰撞变形过程的影响,分析了流体桥、旋转角度等因素的变化情况。Abstract: In this work, the dynamical collision process between two miscible/immiscible micro-droplets is simulated by a modified smoothed particle hydrodynamics (C-SPH) method. In order to improve the numerical accuracy and stability of traditional SPH method, a kernel gradient modified scheme without kernel derivative is considered. Meanwhile, an improved surface tension technique based on the van der Waals model is adopted to deal with the moving interface. The reliability of C-SPH method of simulating the deformation process between two droplet collisions is tested through the numerical simulations of coalescence process between two miscible Newtonian droplet collisions. Subsequently, the coalescence process of miscible polymer droplet collision and the deforma-tion process of bouncing and separation between two immiscible droplet collisions are investigated, in which the control equations of droplets are all based on the van der Waals model. The influences of the collision velocity, collision angle and the density ratio on the deformation process of collision are discussed, and the changes of liquid bridge and rotation angle are analyzed.
-
-
计量
- 文章访问数: 518
- HTML全文浏览数: 247
- PDF下载数: 0
- 施引文献: 0