Abstract:
Determination of the ship hull resistance has always been a challenging task for the
ship designers. Although experimental methods such as towing tank tests are very
accurate and reliable, conducting towing tank tests is very time consuming and
expensive. For these reasons, now-a-days Computational Fluid Dynamics (CFD)
techniques are frequently used for prediction of ship hull resistance.
The goal of this thesis is to carry out a detailed numerical investigation by utilizing
two RaNSE based dedicated naval CFD solvers WISDAM (Wave vIScous
ow Dif-
ference Accurate Method) and steadyNavalFoam for prediction of ship resistance in
calm water. Computations for two benchmark container ship models KCS (KRISO
Container Ship) and SR108 are made.
In the present work, the viscous
ow around the ship hull are represented by the
Reynolds-averaged Navier-Stokes Equations (RaNSE) and the continuity equation
for
uid velocity and pressure. The
uid is assumed viscous and incompressible,
and the
ow eld were considered turbulent. These numerical codes utilize the
nite volume method to discretize the governing equations. Structured hexahe-
dral mesh is used in case of WISDAM. In steadyNavalFoam, both structured and
unstructured hexahedral mesh were used. For free surface treatment, WISDAM
utilizes the Marker Density Function Method (MDF) and steadyNavalFoam utilizes
the Volume of Fluid (VOF) approach. For turbulence modeling, the k ! SST
model is used in the steadyNavalFoam code. In WISDAM, a combination of the
Dynamic sub grid scale (DSGS) model and the Baldwin-Lomax turbulence model
is used.
The computational results are presented in a non-dimensional form. The contours
of
ow properties are also visualized. The results from KCS were compared with ex-
perimental results from Tokyo CFD Workshop 2015. However, lack of experimental
data made it di cult to validate the resistance computed for SR108. The results
obtained for the calm water resistance for KCS by steadyNavalFoam is satisfactory
when compared to experimental data. However, WISDAM results show a large
deviation from the experimental data for KCS. It has also been found that com-
puted values of calm water resistance by WISDAM for SR108 were signi cantly less
than those computed by steadyNavalFoam. The geometry of the two containership
hulls also played a dominant role in the wave elevation and pressure and velocity
distribution.
