Predictionofflow-inducedexcitationinapipeconveyingfluidOriginalResearchArticle

Experimentallyitisevidentthatthenatureoftheflow-inducedexcitationinapipeconveyingfluidisabroadbandfrequencyexcitation.Itisalsoobservedthattheamplitudeofexcitationdecreaseswithincreaseinfrequency.However,thereisnomethodtoestimatesuchforces.Themeasurementofexcitationforceallalongthelengthofapipeusingthepressuretransducersmaybedifficultorperhapsimpossible.Anotherpossibilityistomeasurethestructuralresponsesusingvibrationtransducersallalongthepipelengthandthenestimatetheflow-inducedexcitationforces(bothamplitudeandphase)usingafiniteelement(FE)modelofthepipe.However,themeasureddegreeoffreedoms(dofs)arealwaysmuchsmallerthanthedofsinFEmodel,henceamethodhasbeendevelopedthatusesnon-linearoptimizationmethodinvolvingthelimitedmeasuredresponsestogetherwithFEmodeltopredicttheexcitationforces(bothamplitudeandphase)actingallalongthepipeconveyingfluid.Thepredictedexcitationforcescanthenbeusedtoperformsafetyrelatedstudybyassessingthepiperesponsesatanylocationwhetheraccessibleornot.Thetheoryoftheproposedmethodanditsvalidationhasbeenpresentedinthepaperthroughalongstraightpipeconveyingfluid.Typicalapplicationsoftheproposedmethodarealsodiscussed.