Mechanical Systems Mechanical Systems 0.2mm55AssociateProfessorPhD Engineering 1995, Nagoya University.Faculty: Nagoya University, 1994-1997.Faculty: Shinshu University, 1997-AssistantProfessorAftercompletingPhDatKeioUniveristyin2017andpostdocworkatKTH(Stockholm)by2021,thecurrenttitlefrom2022.Themaininterestisfluidmechanics,ofstatistics/vorticalstructure,opticalmeasurementandflowcontrol.EngineeringEngineeringOurmainresearchinterestfluiddynamics.Currentresearchprojectsare:directnumericalsimulationsofflowsoveranopencavity,includingstudiesoftheeffectsofcavityaspectratioonself-sustainedoscillationsofseparatedshearlayerandrecirculatingvorticesinthecavity;activecontrolofcavityflow;directnumericalsimulationsofjet–edgesystem;directandlargeeddysimulationsoftwo-dimensionalturbulentjets.Takashi YoshidaLaminar-turbulenttransition(fromasmoothflowtoachaoticflowcontainingdifferentvortices)hasbeenstudiedasitaffectstheefficiencyoffluid/transportmachinerythroughdramaticchangesoftheflowproperty,e.g.,friction/pressuredragandheattransfer.Whydothesevorticescomeup?Howstrongcouldtheybecome?Canwecontrolthevorticesforindustrialapplications?Wearetryingtoanswertheseissues,studyingthecharacteristicsofvorticesinthree-dimensionalflowswithProf.MasaharuMatsubara.Kentaro KatoTheNavier-Stokesequations,thatarethemomentumequationsofflow,arenonliniear.Thussolvingtheseequationsisverydifficult.NumericalsolutionsoftheNavier-Stokesequationsforcomplexflowscanbeobtainedusingsupercomputers.Wecaninvestigatethemechanismofcomplexflowusingadvancedsupercomputers.Fundamentalunderstandingofthecharacteristicsofvorticesisessentialtodesign/controltheflowsandrelatedsystemseffectively.Usingsimplifiedmodels,westudyvorticesspeciallyonacurved/rotatingsurfaces,whichexistubiquitouslyonrealapplicationssuchasturbines,propellers,centrifugalseparators,windfarms,etc.analysisiscomputationalfromnumericalsimulationsforNumericalsimulationhasbeenausefulengineeringdesignandanalysis.Alumnusfromourlaboratoryareworkingasmechanicalengineers,mechanicaldesigners,softwaredesigners,systemengineers,etc.toolSpiralcross-flowvorticesoverabroadrotatingcone,whosecollapseleadstotransition.Thisflowhasbeeninvestigatedasacanonicalmodeltostudythesimilarvorticesdevelopingonswept/deltawings.Vorticalstructuresatthecrosssections(a-c)(obtainedfromhot-wiremeasurements;Katoetal.Phys.Rev.Fluids,4,053903,2019)Isosurfaces of vorticity in flow over cavity. The left figure shows an uncontrolled flow and the right figure shows a controlled flow. Isosurfaces of vorticity in a two-dimensional turbulent jet.In the FutureAfter Graduationtheonset,developmentandcollapseofIn the FutureAfter GraduationThroughourexperimentsandanalysis,westudynotonlyfluidmechanics,butalsovariousdisciplines,suchaselectronics,optics,andcontrolusingprogramming.Suchexperiencesmakeusevenmoreactiveinfindingandsolvingproblemsoverpreviousbordersamongdifferentdisciplinesaswellasopenmoreopportunitiesforourcareers.Where do the Vortices come from?Why do they Collapse?Numerical Simulations of Flows using high performance computing
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