Part icle size and density
Figure 3.34 illustrates the catch probability as a function
of particle size for different particle densities. The catch
probability in this study indicates the probability of a particle
to remain in front of the boom for the duration of the
experiment.
For this experiment, the closed V setup with a boom angle
of 45° and flow speed 0.1 m/s was used. In the experiment
the particle behavior was simulated for 15 minutes.
During each experiment, 100 particles were released. The
particles are randomly distributed from the surface down
to 3 m depth at a distance of 35 m from the boom.
The results show that it will be quite unlikely to catch a
particle with a diameter of less than 0.1 mm, because
even with the lowest density of 940 kg/m³ almost all particles
escape the barrier. With increasing particle size,
the catch probability increases as well. For all simulated
densities, particles with a diameter of larger than 2 mm
show a catch probability close to 1. They seem to have
enough buoyancy to withstand the drag forces of the
ocean that pull them downwards.
Boom angle
The graph below (Figure 3.35) illustrates the change in
catch probability when changing the barrier angle. Again,
the small setup of closed V with a 6 m flow box is used.
The particles are released at a 35 m distance to the barrier.
Particle density is set at 1000 kg/m³ and particle size
is 0.5 mm.
From simulations with barrier angles of 10, 20 and 45 degrees,
it can be seen that the catch probability slightly
increases for increasing barrier angle.