Numerical modeling of the hydrodynamics of standing wave and scouring in front of impermeable breakwater with different steepnesses

Abstract

The aimofthispaperistonumericallystudytheeffectsofbreakwatersteepnessonthehydrodynamics of standingwaveandscouringprocessinfrontofimpermeablebreakwaters.Atwo-dimensional hydrodynamicsmodelbasedontheReynoldsAveragedNavier–Stokes(RANS)equationsandtheVolume of Fluid(VOF)methodwasdevelopedandthencombinedwithanempiricalsedimenttransportmodel. Comparisons withananalyticalsolutionandexperimentaldatashowedthepresentmodelisvery accurateinpredictingthenearbottomvelocityandcapableofsimulatingthescour/depositionpatterns consistent withexperimentaldata.Itwasfoundthattheadditionaltermsofbottomshearstressinthe momentum equationsarenecessarytoproduceaphysicalscouringpattern.Differentbreakwater steepnesses producedifferentcharacteristicsofstandingwave,thesteadystreamingsystem,and scouring patterninfrontofthebreakwaters,whichalsoaffectsthecorrelationsbetweenthem.An additional analysisoftheturbulence field parametersandthesedimenttransportratewasalso performed. Alltheseimportantinformationwillbepresentedindetailsinthispaperandcanbe worthwhile fordesigningthebreakwaterincoastalareas.