Structural Analysis of Oil-Spill Booms - Mathematical Modelling and Numerical Simulation of Oil Pollution Problems - page 161

Fig. 7.16 Fiber D for barrier and curtain skirts

the boom mesh can be made by proposing a numerical stretching of the float nodes
every 5m.
The geometries of the Elorn boom given by GPS measure, 2D and 3D computa-
tions are in relatively good agreement. These geometries depend on the environmen-
tal conditions. Experimental and numerical approaches must be based on the same
environmental data. The Elorn boom uses mooring lines connected to the buoyancy
coffers. The boom mesh can be improved to take into account the mooring lengths.
Along the Elorn boom, the numerical evaluation of the skirt angle follows qual-
itatively the experimental evaluation of the skirt angle by sticks. A more precise
comparison between numerical and experimental approaches can be made in an
hydrodynamic channel at a reduced scale.
The above Fig. 7.16 illustrates the vertical injection between the curvilinear
domain c and the boom surface

for both barrier and curtain designs. The Fig. 7.16
presents the manifold of fibers D constructed by using the skirt angle

ˉ

ʸ . When ʸ = 0

the bottom part of the ruban r = c × D corresponds to the non-deformed boom skirt.

For other values the ruban approximates the deformed boom skirt.

The knowledge of the ruban r is a modelling and operational challenge for oil-spill
contingency plan. The installation of a physical measure of one fiber on a barrier
during La Rochelle preparatory experiment is shown on Fig. 7.2 .

ʸ

7.5 Conclusions

The main results are the reliability of the 2D cable model to represent a boom device
during its mooring in the environment, and the ability of the 3D model results, ini-
tialized by using the previous 2D solution, to evaluate the oil containment efficiency
and the structural safety. The principal advantage of the proposed approach is to
show both numerical method and operational experiment on a same boom part of