简介:Uptonow,therearenosatisfactorynumericalmethodsforsimulatingwaveresistanceoftrimarans,mainlyduetothedifficultyrelatedwiththestrongnonlinearfeaturesofthepiecehullwavemakingandtheirinterference.Thisarticleproposesanumericalmethodforquickandeffectivecalculationofwaveresistanceoftrimaranstobeusedinengineeringapplications.BasedonWyatt'swork,thenonlinearfreesurfaceboundarycondition,thetimedomainconcept,andthefullnonlinearwavemakingtheory,usingtheRankinesourceGreenfunction,the3-Dsurfacepanelmethodisexpandedtosolvethetrimaranwavemakingproblems,withhighordernonlinearfactorsbeingtakenintoaccount,suchastheinfluenceofthesinkingandtrim,transom,andshipwaveimmersedhullsurface.Andthesoftwareissuccessfullydevelopedtoimplementthemethod,whichisvalidated.Severaltrimaranmodels,includingapracticaltrimaranwithasonardomeandthetransom,areusedasnumericalcalculationsamples,theirwavemakingresistanceiscalculatedbothbythepresentmethodandsomeothermethodssuchaslinear(Dawson)methods.Moreover,samplemodelresistancetestswerecarriedouttoprovidedataforcomparison,validationandanalysis.Throughthevalidationbymodelexperiments,itisconcludedthatpresentmethodcanwellpredictthewavemakingresistance,sinkingandtrim,andtheaccuracyofwavemakingresistancecalculationissignificantlyimprovedbytakingthetrimandsinkingintoaccount,especiallyathighspeeds.
简介:Duringthedevelopmentoflowpermeabilityreservoirs.theinteractionbetweenfluidflowandrock-massdeformationisobvious.Onthebasisoffluidmechanicsinporousmediaandelasto-plastictheory.theauthorpresentsanequivalentcontinuummodeltosimulatefluidflowinfracturedlow-permeabilityoilreservoircoupledwithgeo-stress.Themodelnotonlyreflectstheporositychangeofmatrix,butalsothepermeabilitychangeduetotheopeningandclosingoffracture.Byanalyzingofsimulationresults,thechangesinporosityandpermeabilityandtheireffectonoildevelopmentarestudied.