scholarly journals A numerical method for two-phase flow in micro channels and its application to droplet control by electrowetting on dielectric

2006 ◽  
Vol 55 (3) ◽  
pp. 1005
Author(s):  
Wang Fei ◽  
He Feng
Keyword(s):  
Numerical Method ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Electrowetting On Dielectric ◽  
Micro Channels ◽  
Droplet Control

Two-Phase Flow and Heat Transfer in Rectangular Micro-Channels

2003 ◽  
Author(s):  
Weilin Qu ◽  
Seok-Mann Yoon ◽  
Issam Mudawar
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Heat Sinks ◽  
Phase Flow ◽  
Micro Channel ◽  
Two Phase ◽  
Micro Channels

Knowledge of flow pattern and flow pattern transitions is essential to the development of reliable predictive tools for pressure drop and heat transfer in two-phase micro-channel heat sinks. In the present study, experiments were conducted with adiabatic nitrogen-water two-phase flow in a rectangular micro-channel having a 0.406 × 2.032 mm cross-section. Superficial velocities of nitrogen and water ranged from 0.08 to 81.92 m/s and 0.04 to 10.24 m/s, respectively. Flow patterns were first identified using high-speed video imaging, and still photos were then taken for representative patterns. Results reveal that the dominant flow patterns are slug and annular, with bubbly flow occurring only occasionally; stratified and churn flow were never observed. A flow pattern map was constructed and compared with previous maps and predictions of flow pattern transition models. Annual flow is identified as the dominant flow pattern for conditions relevant to two-phase micro-channel heat sinks, and forms the basis for development of a theoretical model for both pressure drop and heat transfer in micro-channels. Features unique to two-phase micro-channel flow, such as laminar liquid and gas flows, smooth liquid-gas interface, and strong entrainment and deposition effects are incorporated into the model. The model shows good agreement with experimental data for water-cooled heat sinks.

A Numerical Method for Two-Phase Flow Consisting of Separate Compressible and Incompressible Regions

2001 ◽  
Vol 166 (1) ◽  
pp. 1-27 ◽  
Author(s):  
Rachel Caiden ◽  
Ronald P. Fedkiw ◽  
Chris Anderson
Keyword(s):  
Numerical Method ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase

Variational multi-scale finite element method for the two-phase flow of polymer melt filling process

2019 ◽  
Vol 30 (3) ◽  
pp. 1407-1426 ◽  
Author(s):  
Xuejuan Li ◽  
Ji-Huan He
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Method ◽  
Two Phase Flow ◽  
Polymer Melt ◽  
Phase Flow ◽  
Filling Process ◽  
Two Phase ◽  
Content Type ◽  
Element Method

Purpose The purpose of this paper is to develop an effective numerical algorithm for a gas-melt two-phase flow and use it to simulate a polymer melt filling process. Moreover, the suggested algorithm can deal with the moving interface and discontinuities of unknowns across the interface. Design/methodology/approach The algebraic sub-grid scales-variational multi-scale (ASGS-VMS) finite element method is used to solve the polymer melt filling process. Meanwhile, the time is discretized using the Crank–Nicolson-based split fractional step algorithm to reduce the computational time. The improved level set method is used to capture the melt front interface, and the related equations are discretized by the second-order Taylor–Galerkin scheme in space and the third-order total variation diminishing Runge–Kutta scheme in time. Findings The numerical method is validated by the benchmark problem. Moreover, the viscoelastic polymer melt filling process is investigated in a rectangular cavity. The front interface, pressure field and flow-induced stresses of polymer melt during the filling process are predicted. Overall, this paper presents a VMS method for polymer injection molding. The present numerical method is extremely suitable for two free surface problems. Originality/value For the first time ever, the ASGS-VMS finite element method is performed for the two-phase flow of polymer melt filling process, and an effective numerical method is designed to catch the moving surface.

A Numerical Method for the Analysis of a New Model for Two-Phase Bubbly Flow in Elastic Pipes

2002 ◽  
Author(s):  
D. Kim
Keyword(s):  
Numerical Method ◽  
Surface Deformation ◽  
Two Phase Flow ◽  
Numerical Technique ◽  
Bubbly Flow ◽  
Neumann Boundary ◽  
Phase Flow ◽  
Two Phase ◽  
Tube Cross Section ◽  
Elastic Pipes

A new approach and numerical method for study gas-liquid two-phase flows in elastic pipes is suggested. “A nonlinear wave dynamical model for liquid containing gas bubbles” is applied to derive governing equations for two-phase flow-filled pipelines. On assuming the hydraulic approximation the continuity and momentum equations of two-phase flow in a pipe are obtained for the first time. From these equations the inhomogeneous wave equation of Lighthill-type for two-phase flow in pipelines is derived. The shear stress at the tube surface, deformation of the tube cross-section, and liquid’s phase compressibility are taken into account. A high effectively and accurate finite difference technique for the exact solution of the basic equations in the case of Neumann boundary conditions is developed. Based on the proposed algorithm various numerical experiments have been carried out to investigate the major fluid dynamical features of hydraulic shocks and shock waves in the horizontal pipes. Comparisons with both the experimental data and computational results obtained with a second-order accurate predictor-corrector method support our numerical technique as well as the model.

Application of Preconditioning Method to Gas-Liquid Two-Phase Flow Computations

2003 ◽  
Author(s):  
Byeong Rog Shin ◽  
Satoru Yamamoto ◽  
Xin Yuan
Keyword(s):  
Numerical Method ◽  
Incompressible Flows ◽  
Two Phase Flow ◽  
Tvd Scheme ◽  
Phase Flow ◽  
Internal Flows ◽  
Two Phase ◽  
Time Stepping ◽  
Dual Time Stepping ◽  
Preconditioning Method

A preconditioned numerical method for gas-liquid two-phase flows is applied to solve cavitating flow. The present method employs a finite-difference method of dual time-stepping integration procedure and Roe’s flux difference splitting approximation with MUSCL-TVD scheme. A homogeneous equilibrium cavitation model is used. The present density based numerical method permits simple treatment of the whole gas-liquid two-phase flow field including wave propagation, large density changes and incompressible flows characteristics at low Mach number. By this method, two-dimensional internal flows through a backward-facing step duct, a venturi tube and decelerating cascades are computed. Comparisons of predicted results with experiments are provided and discussed.

Upwind Solutions for Two-Phase Flow Problems Using a Hyperbolic Two-Fluid Model

2011 ◽  
Author(s):  
Moon-Sun Chung ◽  
Youn-Gyu Jung ◽  
Sung-Jae Yi
Keyword(s):  
Numerical Method ◽  
Two Phase Flow ◽  
Fluid Model ◽  
Equation System ◽  
Benchmark Problems ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Problems ◽  
Complete Set ◽  
Two Fluid Model

This study discusses on the implementation of an upwind method for a new 2-dimensional 2-fluid model including the surface tension effect in the momentum equations. This model consists of a complete set of 8 equations including 2-mass, 4-momentum, and 2-internal energy conservation equations having all real eigenvalues. Based on this equation system with upwind numerical method, the present authors first make a pilot 2-dimensional code and then solve some benchmark problems to verify whether this model and numerical method is able to properly solve some fundamental one-dimensional two-phase flow problems or not.

Heat transfer and fluid dynamics of air–water two-phase flow in micro-channels

2010 ◽  
Vol 34 (4) ◽  
pp. 446-453 ◽  
Author(s):  
Masuo Kaji ◽  
Toru Sawai ◽  
Yosuke Kagi ◽  
Tadanobu Ueda
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Micro Channels

Application of Preconditioning Method to Gas-Liquid Two-Phase Flow Computations

2004 ◽  
Vol 126 (4) ◽  
pp. 605-612 ◽  
Author(s):  
Byeong Rog Shin ◽  
Satoru Yamamoto ◽  
Xin Yuan
Keyword(s):  
Numerical Method ◽  
Two Phase Flow ◽  
Flow Characteristics ◽  
Tvd Scheme ◽  
Phase Flow ◽  
Internal Flows ◽  
Two Phase ◽  
Time Stepping ◽  
Dual Time Stepping ◽  
Preconditioning Method

A preconditioned numerical method for gas-liquid two-phase flows is applied to solve cavitating flow. The present method employs a finite-difference method of the dual time-stepping integration procedure and Roe’s flux difference splitting approximation with the MUSCL-TVD scheme. A homogeneous equilibrium cavitation model is used. The present density-based numerical method permits simple treatment of the whole gas-liquid two-phase flow field, including wave propagation, large density changes and incompressible flow characteristics at low Mach number. Two-dimensional internal flows through a backward-facing step duct, convergent-divergent nozzles and decelerating cascades are computed using this method. Comparisons of predicted and experimental results are provided and discussed.

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