dc.contributor.advisor |
Darwish, Marwan |
dc.contributor.author |
Alloush, Mhamad Mahdi |
dc.date.accessioned |
2020-11-04T05:21:04Z |
dc.date.available |
2020-11-04T05:21:04Z |
dc.date.issued |
11/4/2020 |
dc.identifier.uri |
http://hdl.handle.net/10938/22150 |
dc.description |
Luca Mangani
Fadl Moukalled
Nesreene Ghaddar
Kamel Aboughali
Nabil Nassif
Abdellah Kharicha |
dc.description.abstract |
In this thesis, the development of a fully coupled finite volume based free
surface flow solver is presented in details. The approach is based on the volume of
fluid method (VOF) but extends it to account for a range of couplings, including
velocity-pressure, velocity-volume fraction, volume fraction-velocity and volume
fraction-pressure couplings. This results in a matrix of coefficients formed at
each control volume. Accounting for the various couplings leads to an improved
convergence and robustness as compared to segregated type solvers, especially
for steady-state applications but also for transient free surface flows. The solver
is additionally equipped with a number of techniques, including the treatment of
the body forces at the free surface to guarantee a force-balanced solution; this
treatment is evaluated analytically and numerically. Also, a very important facet
to ensure the geometric constraint is provided in the solver; this is represented
by the summation of all volume fractions being enforced to one. In this thesis, a
novel implicit approach to enforce this constraint is presented and is compared to
standard approaches currently in use. Compressive schemes are also addressed
in this work and incorporated in the solver in order to capture the interface
with high accuracy and fidelity. The solver also handles turbulence modeling
infrastructure for turbulent free surface flows with a set of two- and four-equation
models. Worth mentioning is that the performance of the coupled VOF solver
is compared to that of a very popular commercial solver which also features a
coupled VOF solver. On the other hand, accuracy of the results is evaluated in the
light of experimental data along with data generated by the commercial solver.
A range of free surface problems exhibiting a variety of boundary conditions and
different levels of complexity are attempted. A transient 2D forced sloshing test
case is first simulated and the progress of the free surface at a predefined point is
monitored in time; it shows consistent results with experimental data. A 3D dam
break problem, a very popular free surface testing benchmark, is also simulated; it also produces results comparable to experimental data. Two other steady-state
test cases featuring open channel flows past a cylinder and a submerged hydrofoil
respectively are simulated. Drag monitors for the two cases show a competitive
convergence rate as compared to the commercial software. |
dc.language.iso |
en |
dc.subject |
VOF; free surface; CFD; coupled |
dc.title |
The Development of a Fully Coupled Solver for the Solution of Free Surface Flows |
dc.type |
Dissertation |
dc.contributor.department |
Department of Mechanical Engineering |
dc.contributor.faculty |
Maroun Semaan Faculty of Engineering and Architecture |
dc.contributor.institution |
American University of Beirut |