A combined immersed boundary/phase-field method for simulating two-phase pipe flows
File(s)
Author(s)
Argyropoulos, Christos
Type
Thesis
Abstract
The investigation of the flow in a pipe is a major issue for the pipeline capacity but
also plays an important role for the control and prevention of phenomena that could
damage the pipe, such as corrosion, erosion, and the potential formation of wax or their
deposits. Therefore, the characterization of the flow patterns is also a major issue for the
prediction of the distribution over the cross-section of the pipe, in order to understand
any problems that may interrupt or shut down the operation of the production line.
The main purpose of the present effort is to develop an appropriate numerical method
for simulating two-phase pipe flows. Advanced Computational Fluid Dynamics (CFD)
methods are employed as Navier-Stokes solver, while a Phase-Field method is used to
simulate the interfacial region between the two fluids. A Ghost-Cell Immersed Boundary
Method (GCIBM) was developed and implemented for the reconstruction of smooth rigid
boundaries (pipe wall) based on the work of Tseng and Ferziger (2003). The method was
also modified in order to incorporate appropriate boundary conditions for coupling the
Phase-Field and Navier-Stokes solvers for two-phase pipe flows. Tseng and Ferziger (2003)
used the GCIBM for turbulent single-phase flows; the present modified version comprises
a continuation of the method for handling two-phase pipe flows. The computational
model is capable of handling large density and viscosity ratios with good accuracy.
The developed GCIBM algorithm was validated against analytical solutions for single and
two-phase pipe flow, presenting very good agreement. The computational model was
compared to available experimental data from the literature for single rising bubbles and
bubble coalescence in vertical pipe also with good agreement. The numerical method was
used to investigate the lateral wall effects of a 3-D single bubble in a viscous liquid for
different pipe diameters and bubble flow regimes. The dynamics of 3-D Taylor bubbles
was also examined in vertical pipes for different properties of fluids (e.g. air-water system)
and dimensionless parameters relevant to the problem (e.g. ReB, Eo, Mo). The numerical
results were compared with available experimental and numerical data from the literature,
presenting good agreement.
also plays an important role for the control and prevention of phenomena that could
damage the pipe, such as corrosion, erosion, and the potential formation of wax or their
deposits. Therefore, the characterization of the flow patterns is also a major issue for the
prediction of the distribution over the cross-section of the pipe, in order to understand
any problems that may interrupt or shut down the operation of the production line.
The main purpose of the present effort is to develop an appropriate numerical method
for simulating two-phase pipe flows. Advanced Computational Fluid Dynamics (CFD)
methods are employed as Navier-Stokes solver, while a Phase-Field method is used to
simulate the interfacial region between the two fluids. A Ghost-Cell Immersed Boundary
Method (GCIBM) was developed and implemented for the reconstruction of smooth rigid
boundaries (pipe wall) based on the work of Tseng and Ferziger (2003). The method was
also modified in order to incorporate appropriate boundary conditions for coupling the
Phase-Field and Navier-Stokes solvers for two-phase pipe flows. Tseng and Ferziger (2003)
used the GCIBM for turbulent single-phase flows; the present modified version comprises
a continuation of the method for handling two-phase pipe flows. The computational
model is capable of handling large density and viscosity ratios with good accuracy.
The developed GCIBM algorithm was validated against analytical solutions for single and
two-phase pipe flow, presenting very good agreement. The computational model was
compared to available experimental data from the literature for single rising bubbles and
bubble coalescence in vertical pipe also with good agreement. The numerical method was
used to investigate the lateral wall effects of a 3-D single bubble in a viscous liquid for
different pipe diameters and bubble flow regimes. The dynamics of 3-D Taylor bubbles
was also examined in vertical pipes for different properties of fluids (e.g. air-water system)
and dimensionless parameters relevant to the problem (e.g. ReB, Eo, Mo). The numerical
results were compared with available experimental and numerical data from the literature,
presenting good agreement.
Version
Open Access
Date Issued
2015-03
Date Awarded
2015-08
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
License URL
Advisor
Boek, Edo
Sponsor
Engineering and Physical Sciences Research Council
Publisher Department
Chemical Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)