摘要
Theheattransferfromanelectricallyheatedcylinder(wire)offinitelengthtothesurroundingfluidcanbedividedintoheatradiation,conductionandconvection.Atechnicalapplicationofthesecylinderswithtypicaldimensionsof1-2mmlengthandafewmicrometersdiameteristheHot-Wire-Anemometry.Thissystematicstudyshouldclarifytheinfluenceoffreeconvectiontothreedimensionalheattransferofcylinders.forthisaimitisplannedtoinvestigateReynoldsnumbersbelowRe=1(creepingflow).Forthisreasonmeasurementsshouldbedoneunder1gintheearthlaboratoryandalsoundermicrogravity(μg)conditions.Comparisonsofthesemeasurementsunderotherwisesameconditionsallowstodistinguishbetweenthepureconvectionheattransferandthecontributionsduetoconductionandothereffects.FormeasurementsunderμgtheDropTowerBremencanbeusedasresearchfacility.DuetothefastresponseofconvectiontochangesinthegravityconditionstheDropTowerisanidealandcostefficientexperimentaltool.Theexperimentalsetupisbuildtooperateatvelocityrangeof0-1m/swhichincludesthewholerangeofconvectionfrompurefreeconvectionat0m/sovermixedconvectionuptopureforcedconvectionatvelocitiesaboveabout0.15m/s.ThisvelocityregioncorrespondstoarangeoftheReynoldsnumberofRe=0-0.18foracylinderof5μmdiameteratTf=140℃inairatanambienttemperatureofabout21℃.
出版日期
2001年01月11日（中国期刊网平台首次上网日期，不代表论文的发表时间）
