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《基于振蕩熱管液膜數(shù)值模擬和特性的分析》由會(huì)員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫(kù)。
1、摘要摘要本文以液膜為切入點(diǎn),利用ANSYSFLUENT軟件對(duì)振蕩熱管進(jìn)行了數(shù)值模擬研究,以揭示振蕩熱管的啟動(dòng)和運(yùn)行機(jī)理。振蕩熱管的構(gòu)造簡(jiǎn)單,但工作原理和管內(nèi)流動(dòng)非常復(fù)雜,管徑、充液率、工質(zhì)種類、加熱量、布置傾角等影響因素如果設(shè)置不當(dāng),都可能造成熱管不能順利啟動(dòng)和工作,所以本文首先分析了對(duì)振蕩熱管有重要影響的幾何物理因素,用以確定模擬時(shí)應(yīng)該采用的管型尺寸和工作條件。其次本文考慮到振蕩熱管存在的尺度效應(yīng)可能對(duì)模擬結(jié)果產(chǎn)生的影響,分析了振蕩熱管及其液膜的微尺度效應(yīng),結(jié)合管內(nèi)液膜理論確定模擬中應(yīng)該注意的諸如表面張力、壁面粘附、接觸角等細(xì)節(jié)問(wèn)題。振蕩熱管為封閉流場(chǎng)中的無(wú)初始勢(shì)差非穩(wěn)態(tài)相變傳熱傳質(zhì)問(wèn)題,加
2、之流場(chǎng)狹長(zhǎng)流動(dòng)復(fù)雜,其模擬量和模擬難度均較大,針對(duì)模擬過(guò)程中可能遇到的設(shè)置障礙,本文分析了模擬應(yīng)該采用的網(wǎng)格類型、求解模式、精度格式、流動(dòng)模型等模擬環(huán)節(jié)的操作問(wèn)題,并對(duì)其中的一些物理量取值和參數(shù)的確定做了充分準(zhǔn)備。最后,本文通過(guò)多種模型的模擬結(jié)果分析了振蕩熱管中氣泡初生時(shí)液膜的形成和發(fā)展、在壁面粘附情況下氣塞、液塞氣塞、液塞交界面處液膜的形態(tài)變化、熱管啟動(dòng)過(guò)程中液膜的傳熱傳質(zhì)作用、以及運(yùn)行中液膜波動(dòng)變化引起的流場(chǎng)流態(tài)變化。關(guān)鍵詞:液膜;振蕩熱管:數(shù)值模擬:特性分析:微尺度效應(yīng)AbstractNumericalsimulationandanalysisoncharacteristicofthel
3、iquidfilmarecarriedontorepresenttheprocessmechanismofstartingandoperatingofoscillatingheatpipebyexploitingANSYSFLUENTsoftwareinthispaper.Theoscillatingheatpipehassimplestructure,butitsworkprincipleandfloWcharacteristicsareverycomplicated.Ifaffectfactorsaresetinappropriately,forexamplediameterofthepi
4、pe,liquid-filledrate,typeofworkingfluid,quantityofheating,angleofarrangementandSOon,theprocessofstartingandoperatingcannotcarryoutnormally.Inordertodefinethepipesizeandworkingconditionsduringsimulation,geometryandphysicalfactorswhichhaveanimportantimpactonoscillatingheatpipeareanalyzedfirstly.Duetot
5、hepossibleinfluenceofscaleeffectofoscillatingheatpipeonsimulationresults,microscaleeffectofoscillatingheatpipeanditsliquidfilmarebothanalyzedandsomedetailproblemshouldbenoticedcombiningliquidfilmtheoryofthepipeduringsimulationsecondly,suchas,surfacetension,walladhesion,contactangleandSOon.Theprocess
6、ofoscillatingheatpipeisproblemofclosedflowfield,noinitialpotentialdifference,unsteady,phasetransition,heatandmasstransfer.Forobstaclesmaybeencounteredandthesituationofnarrowandcomplexflowfieldwhichlcadtoquantityanddifficultyofsimulationincrease,SOoperationalproblemsofmeshtype,solutioncontrols,precis
7、ionformatandflowmodelareanalyzedandsomedefinitionofphysicalvaluesandparameterspreparedfullyforthesimulationofthispaper.Simulationresultsareobtainedbyalotofmodelformwhichtheformationanddevelopmentofliq