Test 12
2D Wave interaction with floating body.
By Alex Crespo (Universidade de Vigo)
and Andrea Colagrossi (INSEAN)
(Download full test case data files here: SPHERIC_TestCase12.zip)
Introduction
The test proposed here is a good benchmark to validate the interaction
of the fluid with rigid floating bodies and the correct buoyancy of the objects.
Hence, the study of a floating body subjected to a wave packet is validated
with experimental data. At the focusing point the wave packet is quite steep
and has a height equal to the body. Then, a nonlinear behaviour is observed in
both the resulting wave evolution and the body motion.
Flow phenomena
Buoyancy,
nonlinear waves. Measure of motion and rotation of a rigid body.
Geometry
The setup of the experiment is shown in the figure below. The floating
body is a rectangular prism 10 cm long, 5 cm high and 29 cm wide, with density
relative to water being 0.68. The mass of the body (aluminum box) is 0.986 kg
in 3D and the moment of inertia is 14 kg cm^2, but the simulation is
performed in 2D. The black line is the flap wavemaker that follows a prescribed
motion (see “Boundary Conditions” section). The center of the box is at 2.11 m
from the flap. The experiment is fully described in Hǎdzić et al. (2005) and XingKaeding
(2006).
Figure 1. Setup of the experiment described in Hǎdzić et al. (2005).
Boundary
conditions
The file Flap.dat contains two columns which are respectively: time and degrees
of rotation of the flap. The axis of rotation of the flap is its position at
the bottom. The figure shows the time history of the flap wavemaker angle used
to generate the wave packet.
Figure 2. Time series of the flap wavemaker angle.
Initial
conditions
Gravity is acting on the fluid. The geometry initial conditions are
reported in the “Geometry” section.
Results
specification
During the experiments the surface elevation was recorded by two fixed
probes; one before the location of the body (x=1.16m) and other after the body
(x=2.66m). In addition, the time histories of the 2D floating body motions
(sway and heave) and the 2D rotation (roll angle) were also measured.
Results format
The time histories of surface elevation (Probe_N1 and Probe_N2), the
floating body motions (Heave and Sway) and the rotation (Roll) are available in
the ASCII files: Elevation.dat, Motions.dat, Rotation.dat.
Elevation.dat:
Motions.dat:
Rotation.dat:
Benchmark results
The
present test has been solved with the opensource DualSPHysics.
Different
instants of simulation can be seen in Figure 3.
Figure 3. Different instants of the simulation using DualSPHysics. Colour represents the horizontal velocity of the fluid).
1) Surface
elevation at two locations; one before of the body (x=1.16m) and other after
the body (x=2.66m).
Figure 4. Time series of experimental and numerical freesurface surface elevation.
2)
Floating body motions.
Figure 5. Experimental and numerical time series of the floating body motions (heave and sway).
SPH Publications
using this Case

Bouscasse, B., Colagrossi, A., Marrone, S.,
Antuono, M. “Nonlinear water wave interaction with floating bodies in
SPH”, Journal of Fluids and Structures, 42: 112129, 2013.
 Barreiro A, Crespo AJC, Domínguez JM, GarcíaFeal O, Zabala I, GómezGesteira M. “QuasiStatic Mooring solver implemented in SPH”, Journal of Ocean Engineering and Marine Energy, 2(3): 381396, 2016. doi: 10.1007/s4072201600617.
If you have published results for this case, please email the webmaster
to have your papers added.
References
 Hǎdzić I, Hennig J, Peric M, XingKaeding Y. “Computation of
flowinduced motion of floating bodies”, Applied Mathematical Modelling, 29:
1196–1210, 2005.
XingKaeding, Y. “Unified approach to ship seakeeping and maneuvering by a RANSE method”. PhD Thesis, 2006.