Abstract:
The effectiveness of partial vertical permeable barriers of three different configurations located at a finite distance
from a very large floating structure is analyzed for mitigating the wave-induced response of the structure.
The eigenfunction expansion method is employed to obtain solution in case of normal incidence and the study is
extended to the case of oblique incident waves. In case of normalized incident waves, a detailed analysis of the
results on various physical quantities such as the reflection and transmission coefficients, wave force on the
barrier, free surface elevation, plate deflection, shear force and surface strain on the floating structure are
presented. For the case of oblique incidence, results on reflection coefficient for various structural parameters are
presented. Using Green's identity, energy balance relations are derived in both the cases of normally and obliquely
incident surface waves and certain results for normally incident waves are compared for accuracy. The
study reveals that wave reflection follows an oscillatory pattern and the minima in the oscillatory pattern increase
with an increase in structural porosity. Wave reflection and dissipation attain their optima for the same
wave number irrespective of barrier configurations. Occurrences of wave diffraction are observed in case of long
waves for barriers of varied configurations with a narrow gap which decreases with the introduction of barrier
permeability. Moreover, when the distance between the barrier and the very large floating structure is close to an
integer multiple of half of the wavelength, both the wave reflected by the barrier as well as wave forces acting on
the barrier attains their optima.
