Numerical Simulation of Micro-Droplet Formation in a Coflowing Liquid Using Front Tracking Method

2006 ◽  
Author(s):  
Jinsong Hua ◽  
Jing Lou ◽  
Baili Zhang
Keyword(s):  
Front Tracking ◽  
Droplet Formation ◽  
Continuous Phase ◽  
Tension Force ◽  
Drop Formation ◽  
Interface Tension ◽  
Flowing Fluid ◽  
Tracking Method ◽  
Front Tracking Method ◽  
Flowing System

Micro-droplets can be formed when a disperse liquid is injected via a needle nozzle into another immiscible co-flowing fluid. The mode of droplet formation depends on many factors such as liquid flow rates of the inner disperse phase and outer continuous phase, liquid viscosity, nozzle dimensions, interface tension force, etc. In this paper, the drop formation in a co-flowing system is simulated numerically using front tracking method to investigate the drop formation mechanism, which is very critical in the design of micro-fluidic devices for generating micro-droplets in a controllable manner. One set of Navier-Stokes equations for both liquid phases are solved numerically on a fixed Eulerian two-dimensional cylindrical coordinate mesh to account for the flow dynamics, and the front tracking method is applied to track the movement of the interface between the two immiscible liquids as well as the surface tension force. In this set of governing equations for modeling, the effects of flow inertial, capillary, viscous, and gravitational forces are all accounted to explore the droplet formation modes and dynamics in co-flowing system. The simulations reasonably predict the process of droplet formation in the co-flowing liquid. In addition, the effects of the continuous phase flow speed, viscosity and the interface tension force on droplet formation are investigated.

A fully adaptive front tracking method for the simulation of two phase flows

2014 ◽  
Vol 58 ◽  
pp. 72-82 ◽  
Author(s):  
M.R. Pivello ◽  
M.M. Villar ◽  
R. Serfaty ◽  
A.M. Roma ◽  
A. Silveira-Neto
Keyword(s):  
Front Tracking ◽  
Two Phase Flows ◽  
Two Phase ◽  
Tracking Method ◽  
Front Tracking Method ◽  
Fully Adaptive

Runge-Kutta Discontinuous Galerkin Method with Front Tracking Method for Solving the Compressible Two-Medium Flow on Unstructured Meshes

2016 ◽  
Vol 9 (1) ◽  
pp. 73-91 ◽  
Author(s):  
Haitian Lu ◽  
Jun Zhu ◽  
Chunwu Wang ◽  
Ning Zhao
Keyword(s):  
Galerkin Method ◽  
Discontinuous Galerkin ◽  
Discontinuous Galerkin Method ◽  
Front Tracking ◽  
Unstructured Meshes ◽  
Interfacial Region ◽  
Tracking Method ◽  
Front Tracking Method ◽  
Medium Flow ◽  
Runge Kutta

AbstractIn this paper, we extend using the Runge-Kutta discontinuous Galerkin method together with the front tracking method to simulate the compressible two-medium flow on unstructured meshes. A Riemann problem is constructed in the normal direction in the material interfacial region, with the goal of obtaining a compact, robust and efficient procedure to track the explicit sharp interface precisely. Extensive numerical tests including the gas-gas and gas-liquid flows are provided to show the proposed methodologies possess the capability of enhancing the resolutions nearby the discontinuities inside of the single medium flow and the interfacial vicinities of the two-medium flow in many occasions.

Analysis of dynamic characteristics of bubble rise under a free surface

2020 ◽  
Vol 98 (11) ◽  
pp. 981-992
Author(s):  
Ying Zhang ◽  
Qiang Liu ◽  
Wenbin Li ◽  
Xiaolong Lian ◽  
Jinglun Li ◽  
...  
Keyword(s):  
Free Surface ◽  
Immersed Boundary Method ◽  
Weber Number ◽  
Front Tracking ◽  
Terminal Velocity ◽  
Immersed Boundary ◽  
Tracking Method ◽  
Free Interface ◽  
Front Tracking Method ◽  
Moving Interface

The rising process of a bubble occurs in several natural and industrial apparatuses. This process is computationally studied using the front tracking method for a moving interface whose surface properties are solved in terms of an immersed-boundary method. The results show that the free interface does not influence the bubble before the centroid velocity of the bubble reaches the terminal velocity, which reaches a stable value or fluctuates at it, with the distance h (between the centroid of the bubble and the free surface) reaching a certain value. When the Reynolds number increases, the time to reach terminal velocity will decrease, and the influence of the viscous factor on the terminal velocity is also weakened. The dramatic interaction between a bubble and free surface is beneficial to accelerate film draining out. It is also shown that the shape of the bubble gradually becomes an ellipse as the Weber number (We) decreases, and it is beneficial to reduce the resistance of the bubble. The free surface could accelerate the bubble breaking at high We values.

scholarly journals Numerical Simulation of Bubble Free Rise after Sudden Contraction Using the Front-Tracking Method

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Ying Zhang ◽  
Min Lu ◽  
Wenqiang Shang ◽  
Zhen Xia ◽  
Liang Zeng ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Front Tracking ◽  
Single Bubble ◽  
Tracking Method ◽  
Front Tracking Method ◽  
Sudden Contraction ◽  
Eotvos Number

Based on the front-tracking method (FTM), the movement of a single bubble that rose freely in a transverse ridged tube was simulated to analyze the influence of a contractive channel on the movement of bubbles. The influence of a symmetric contractive channel on the shape, speed, and trajectory of the bubbles was analyzed by contrasting the movement with bubbles in a noncontractive channel. As the research indicates, the bubbles became more flat when they move close to the contractive section of the channel, and the bubbles become less flat when passing through the contractive section. This effect becomes more obvious with an increase in the contractive degree of the channel. The symmetric contractive channel can make the bubbles first decelerate and later accelerate, and this effect is deeply affected by Reynolds number (Re) and Eötvös number (Eo).

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