3.3.1 Problem Descr iption
The problem and geometry considered are sketched in
Figure 3.11. The boom is represented by a half disk of radius
R of 0.5 m, which corresponds to a rough value of
the submerged section of the buoyancy body in the plane
perpendicular to the boom span. A thin obstacle of 2.5 m
depth corresponds to the skirt, thus yielding a total draft
H of 3 m. In the simulation, a skirt thickness of 1 cm is
used. This results in a 1/250 aspect ratio for the skirt. No
ballast representation was included in the simulation.
In the simulation, the skirt and buoyancy body are fixed.
This means that neither the rigid motion induced by the
current nor the elastic deformation of the skirt is taken
into account. Moreover, the effect of waves and wind on
the flow is not taken into account. Two angles are considered
with respect to the vertical, first a 0° angle (the
skirt is entirely vertical), and a 10° deflection of the skirt
downstream.
The capture efficiency of the boom depends on the size
of the plastic particles, their buoyancy and the local flow
velocity.