畢業(yè)論文外文翻譯-密封的建筑排水系統(tǒng)和通氣系統(tǒng)——活性氣壓的瞬變控制和抑制

1、山東建筑大學畢業(yè)設計外文文獻及譯文1外文文獻：外文文獻：Sealedbuildingdrainageventsystems—anapplicationofactiveairpressuretransientcontrolsuppressionAbstractTheintroductionofsealedbuildingdrainageventsystemsisconsideredaviablepropositionfcomplexbui

2、ldingsduetotheuseofactivepressuretransientcontrolsuppressioninthefmofairadmittancevalvespositiveairpressureattenuatscoupledwiththeinterconnectionofthewksverticalstacks.Thispaperpresentsasimulationbasedonafourstackwkthati

3、llustratesflowmechanismswithinthepipewkfollowingbothappliancedisgegeneratedsewerimposedtransients.Thissimulationidentifiestheroleoftheactiveairpressurecontroldevicesinmaintainingsystempressuresatlevelsthatdonotdepletetra

4、pseals.Furthersimulationexerciseswouldbenecessarytoprovideproofofconceptitwouldbeadvantageoustoparallelthesewithlabatypossiblysitetrialsfvalidationpurposes.Despitethiscautiontheinitialresultsarehighlyencouragingaresuffic

5、ienttoconfirmthepotentialtoprovidedefinitebenefitsintermsofenhancedsystemsecurityaswellasincreasedreliabilityreducedinstallationmaterialcosts.Keywds:ActivecontrolTrapretentionTransientpropagationNomenclatureC——acteristic

6、equationsc——wavespeedmsD——branchstackdiametermf——frictionfactUKdefinitionviaDarcyΔh=4fLu22Dgg——accelerationduetogravityms2K——losscoefficientL——pipelengthmp——airpressureNm2t——timesu——meanairvelocitymsx——distancemγ——ratios

7、pecificheats山東建筑大學畢業(yè)設計外文文獻及譯文3openingaspressurefallstoallowareliefairinflowhencelimitthepressureexcursionsexperiencedbytheappliancetrapseal[9].HoweverAAVsdonotaddresstheproblemsofpositiveairpressuretransientpropagationwi

8、thinbuildingdrainageventsystemsasaresultofintermittentclosureofthefreeairpaththroughthewkthearrivalofpositivetransientsgeneratedremotelywithinthesewersystempossiblybysomesurgeeventdownstream—includingheavyrainfallincombi

9、nedsewerapplications.Thedevelopmentofvariablevolumecontainmentattenuats[10]thataredesignedtoabsbairflowdrivenbypositiveairpressuretransientscompletesthenecessarydeviceprovisiontoallowactiveairpressuretransientcontrolsupp

10、ressiontobeintroducedintothedesignofbuildingdrainageventsystemsfboth‘stard’buildingsthoserequiringparticularattentiontobepaidtothesecurityimplicationsofmultiplerooflevelopenstackterminations.Thepositiveairpressureattenua

11、t(PAPA)consistsofavariablevolumebagthatexpsundertheinfluenceofapositivetransienttherefeallowssystemairflowstoattenuategraduallytherefereducingthelevelofpositivetransientsgenerated.TogetherwiththeuseofAAVstheintroductiono

12、fthePAPAdeviceallowsconsiderationofafullysealedbuildingdrainageventsystem.Fig.1illustratesbothAAVPAPAdevicesnotethatthewaterlesssheathtrapactsasanAAVundernegativelinepressure.Fig.1.Activeairpressuretransientsuppressionde