analytical calculation. Hence, in the numerical calculation the calculated forces
were smaller because the strain in the LL results in larger effective maximal
effective sag. The rapprochement to relative force of one for b approaching 30° is
suitable to the theoretic values.
The results present a numerical model with different parametric studies in order
to assess the loads at the fixation of a longline for a worst case scenario. The model
has been verified for the case of a single load point by analytical calculations. The
parametric studies give an overview over the influence of the force angle and h/l
ratio parameters on the forces in the ends of the longline. This study also shows that
in the case of high loads a load reduction could be achieved by an extension of the
LL. Thus, large maximal sag leads to load reduction.
To provide detailed information for the additional loading on the support
structure of offshore wind energy converters, a detailed examination of the sea
states should be taken into account. Factors like wave height and direction as well
as current speed and direction will influence the forces. To estimate the occurrence
of worst-case scenarios, a dynamic analysis should be performed and would be
useful for providing information about inertia forces.
11.4.2 Seaweed Cultivation Devices
In the German North Sea, macroalgal farming of brown algae in offshore environments was launched by the German Government in 1993 and conducted at the
marine Station of the Biologische Anstalt Helgoland (BAH) off the island of
Helgoland, North Sea (see also Sect. 3.1 “Offshore Aquaculture with Extractive
Species: Seaweed and Bivalves”). One major component of this study was to
develop an appropriate technical device to grow macroalgae. The system had to
withstand the harsh environmental conditions of the German North Sea shelf, where
maximum wind speeds can be 150–180 km/h and wave amplitudes commonly
Fig. 11.31 a Model of collector loads for a single collector attached to a longline system;
b Schematic diagram of a buoy and its forces. Modified after Buck et al. 2006b
11 The German Case Study: Pioneer Projects of Aquaculture …
305
were smaller because the strain in the LL results in larger effective maximal
effective sag. The rapprochement to relative force of one for b approaching 30° is
suitable to the theoretic values.
The results present a numerical model with different parametric studies in order
to assess the loads at the fixation of a longline for a worst case scenario. The model
has been verified for the case of a single load point by analytical calculations. The
parametric studies give an overview over the influence of the force angle and h/l
ratio parameters on the forces in the ends of the longline. This study also shows that
in the case of high loads a load reduction could be achieved by an extension of the
LL. Thus, large maximal sag leads to load reduction.
To provide detailed information for the additional loading on the support
structure of offshore wind energy converters, a detailed examination of the sea
states should be taken into account. Factors like wave height and direction as well
as current speed and direction will influence the forces. To estimate the occurrence
of worst-case scenarios, a dynamic analysis should be performed and would be
useful for providing information about inertia forces.
11.4.2 Seaweed Cultivation Devices
In the German North Sea, macroalgal farming of brown algae in offshore environments was launched by the German Government in 1993 and conducted at the
marine Station of the Biologische Anstalt Helgoland (BAH) off the island of
Helgoland, North Sea (see also Sect. 3.1 “Offshore Aquaculture with Extractive
Species: Seaweed and Bivalves”). One major component of this study was to
develop an appropriate technical device to grow macroalgae. The system had to
withstand the harsh environmental conditions of the German North Sea shelf, where
maximum wind speeds can be 150–180 km/h and wave amplitudes commonly
Fig. 11.31 a Model of collector loads for a single collector attached to a longline system;
b Schematic diagram of a buoy and its forces. Modified after Buck et al. 2006b
11 The German Case Study: Pioneer Projects of Aquaculture …
305