WAVE INTERACTION WITH PARABOLIC CORRUGATED AND PERFORATED WAVE ABSORBERS

Abstract

ABSTRACT The wave reflection characteristics of Parabolic (P), Parabolic Corrugated (PC) and Parabolic Corrugated and Perforated (PCP) wave absorbers were investigated using physical models. The profile of the parabolic absorber is Y2 = 0.12 X. The investigations were carried out both with regular and random wave fields for a wide range of wave periods and heights. It is found that the coefficient of reflection, Kr varies from 0.30 to 0.90 for regular waves, when the relative water depth, d/L is decreased from 0.33 to 0.07. For the same range of relative water depths, for the case of random waves, Kr value varies from 0.23 to 0.45 only. Empirical equations are proposed to predict Kr by using Surf Similarity parameter, ξ and relative water depth, d/L as an independent parameter. The relative water depth, d/L is found to be better when compared to ‘ξ’ in predicting the wave reflection from parabolic absorbers. PCP type wave absorber is better by about 5% to 10% when compared to PC and P type wave absorber. All the three wave absorbers are about 5 limes sensitive for change of wave period than change of wave height.