ByusingGAMBITsoftware,thecomputationaldomainofthethrottleclearancewasmeshedinthemixedgridunittypeofhexahedronandwedge.Basedonlaminarflowmodel,threedimensionalnumericalsimulationoftheworkingstateoffloatingring’sthrottleclearanceunderdifferentaxisdiametersandworkingconditionswascarriedoutinFLUENTthroughSIMPLEalgorithm.Twonewequations,oneofwhichcanbeusedtocalculatethecriticalcircumferentialReynoldsnumberforeccentricannularspaceandtheothercanbeusedtocalculateleakagerate,wereobtainedfromthesimulationdata.Theresultsindicatedthattheleakageincreasedwiththeincreaseofeccentricityratio,heightofgapandpressuredrop,whiletheinfluenceoftheaxis’rotationspeedwasnegligible.Theresultslaidafoundationforfurtherinvestigationanddesignofafloatingringseal.