Title of article :
Wavelettime–frequencyanalysisofacceleratinganddeceleratingflowsinatubebankOriginalResearchArticle
Author/Authors :
M.L.S.Indrusiak، نويسنده , , J.V.Goulart، نويسنده , , C.R.Olinto، نويسنده , , S.V.M?ller، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2005
Abstract :
Inthepresentwork,thesteadyapproximationforacceleratinganddeceleratingflowsthroughtubebanksisdiscussed.Withthispurpose,theexperimentalstudyofvelocityandpressurefluctuationsoftransientturbulentcross-flowinatubebankwithsquarearrangementandapitch-to-diameterratioof1.26isperformed.TheReynoldsnumberatsteady-stateflow,computedwiththetubediameterandtheflowvelocityinthenarrowgapbetweenthetubes,is8×104.Airistheworkingfluid.Theacceleratinganddeceleratingtransientsareobtainedbymeansofstartandstopofthecentrifugalblower.Waveletandwaveletpacketmultiresolutionanalysiswereappliedtodecomposethesignalinfrequencyintervals,usingDaubechies20waveletandscalefunctions,thusallowingtheanalysisofphenomenainatime–frequencydomain.Thecontinuouswavelettransformwasalsoapplied,usingtheMorletfunction.Thesignalsinthesteadystate,whichpresentedabistablebehavior,wereseparatedintwomodesandanalyzedwithusualstatistictools.Theresultswerecomparedwiththesteady-stateassumption,demonstratingtheabilityofwaveletsforanalyzingtimevaryingsignals.
Journal title :
Nuclear Engineering and Design Eslah
Journal title :
Nuclear Engineering and Design Eslah
