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1、羅庭:后鼴燈泡貫流泉裝置流動分析摘要貫流泵是適用于大流量、低揚程的一種經(jīng)濟(jì)泵型。具有裝置效率高,水力損失小,過流能力大,機(jī)組結(jié)構(gòu)緊湊,水工布置簡單,土建和運行費用低等優(yōu)點。南水北調(diào)東線工程中許多泵站采用的就是貫流泵裝置。對貫流泵裝置的流動特性進(jìn)行分析,將有助于水泵性能的研究,對工程實際有著重要的指導(dǎo)價值。本文基于RANS方程和RNG肛占紊流模型,對后置燈泡貫流泵裝置內(nèi)部三維紊流流場進(jìn)行了數(shù)值模擬。采用專業(yè)前處理軟件ICEMCFD對進(jìn)出水流道進(jìn)行了建模和網(wǎng)格劃分,采用渦輪葉柵通道網(wǎng)格劃分專業(yè)軟件TurboGrid對葉輪和導(dǎo)葉進(jìn)行了建模和網(wǎng)格劃分。將所形
2、成的結(jié)構(gòu)化網(wǎng)格導(dǎo)入到流體計算軟件CFX內(nèi),來進(jìn)行內(nèi)部流場和外特性研究。通過數(shù)值模擬計算,得到的貫流泵裝置外特性與試驗測量結(jié)果基本一致。利用內(nèi)部流場數(shù)值計算的結(jié)果,分析了后置燈泡貫流泵內(nèi)部流速、壓強(qiáng)的分布情況,對流態(tài)變化較大的導(dǎo)葉段和出水流道燈泡體段進(jìn)行了詳細(xì)的分析。同時對貫流泵裝置各部分水力損失的情況進(jìn)行了計算,發(fā)現(xiàn)在導(dǎo)葉段和出水流道燈泡體段是水力損失最多、隨流量變化晟大的地方,脫流情況比較嚴(yán)重。本文分析討論了出水流道燈泡體段中,不同泵筒和燈泡體結(jié)構(gòu)參數(shù)對裝鷺效率的影響。泵筒尺寸適當(dāng)放大,會使導(dǎo)葉的出流流速不至過大,有助于提高效率。燈泡體尺寸過大,則
3、會使泵效率下降。研究成果為后置燈泡貫流泵性能的提高指明了方向。關(guān)鍵詞:貫流泵數(shù)值模擬流動特性紊流模型cFx揚州大學(xué)碩士論文ABSTRACTForlargedischargeandlowlifthead,itisespeciallysuitabletousetubularpumpsfortheireconomiccharacteristics.Tubularpumpshavehi曲pumpingdevicesefficiency,smallhydraulicloss,strongdischargecapacity,compactunitsstructu
4、re,simpleconstructionarrangementandlowcostbothforconstructionandrunning.NowintheeastrouteofSouthtoNoahWaterDiversionProject,manypumpstationschoosetubularpumpingdevices.ItisimportanttoanalyzetheflOWcharacteristicsandpumpperformanceoftubularpumpingdevicesforitwillbeveryusefulforp
5、racticalengineering.,BasedontheReynolds-AveragedN-SequationandRNGk-6turbulentmodel,thispapersimulatestheinner3Dturbulentflowfieldofpostpositionalbulbtubularpumps.TheinletandoutletconduitsaremodeledandplottedintostructuredgridswithICEMCFD.Andtheimpelleranddiffuseraremodeledandpl
6、ottedintostructuredgridswithTurhoGrid.CFXisusedtomakeafullstudyontheinnerflowfieldandpumpperformance.Tbecalculatedresultsoftheflowfieldindicatesthatthenumericalsimulationtechniqueisfeasible.Withcalculatedresults,thedistributingofvelocityandpressureinsidethepostpositionalbulbtub
7、ularpump,especiallyforthepartsofdiffuserandoutletconduit’Sbulbsection,isobtained.Togetherwiththecalculationforeachpart’Shydraulicloss,weknowthatinthepartsofdiffuserandoutletconduit’Sbulbsectionthereismuchdroppingflowandthemosthydrauliclossthatvariesmostwiththeflow.Thispaperanal
8、yzeshowthesizeofpumpbarrelandbulbaffectstheefficiency.