简介：Thispaperdiscussesnumericalresultsfromthree-dimensionallargeeddysimulationsofanoscillatingcylinderunderprescribedmovementsinuniformflow.Sixcases,namelypurein-line,purecross-flowandtwogroupsof'FigureofEight'oscillationpatternsareunderinvestigationatReynoldsnumberRe=24000.The'FigureofEight'patternineachgroupiswithidenticalshapebutoppositeorbitaldirections.Thenumericalresultsonhydrodynamicforces,higherorderforcecomponents,andvortexsheddingmodesareextensivelystudiedandcomparedwiththemeasuredexperimentaldata.Itisfoundthatthefluidforceinphasewiththevelocity,whichrepresentstheenergytransferbetweenthefluidandthecylinder,hasoppositesignanddifferentmagnitudeduetotheoppositeorbitaldirection.Higherorderforcecomponentsincross-flowdirectionarefoundtooccuratoddnumbertimesoftheoscillatingfrequency,whileevennumbersdominatethehigherorderforcecomponentsinin-linedirection.The2Cand2Tvortexsheddingmodesarewellreproducedduetotheoppositeorbitaldirectioneffect.Comparisonsbetweennumericalandexperimentalresultsindicatethatthepresentnumericalmodelcouldbearationaltoolfortheidentificationofhydrodynamiccoefficientswhicharenormallyappliedinempiricalmodelstopredictthevortex-inducedvibrationsofslendermarinestructures.

简介：Correspondingtotheslidingandtheoverturningfailure,theelementarymotionmodesofcaissonbreakwaterincludethehorizontal-rotationaloscillationcoupledmotion,thehorizontalsliding-rotationaloscillationcoupledmotion,thehorizontalvibrating-upliftrockingcoupledmotion,andthehorizontalsliding-upliftrockingcoupledmotion.Themotionmodeofacaissonwilltransformfromonetoanotherdependingonthewaveforcesandthemotionbehaviorsofthecaisson.Thenumericalmodelsoffourmotionmodesofcaissonaredeveloped,andthenumericalsimulationprocedureforjointmotionprocessofvariousmodesofcaissonbreakwaterunderwaveexcitationispresentedandtestedbyaphysicalmodelexperiment.Itisconcludedthatthesimulationprocedureisreliableandcanbeappliedtothedynamicstabilityanalysisofcaissonbreakwaters.