Heat Transfer Enhancement in a Pipe Using a Flow Inverter

Autor:	Rudolf Žitný, Thi Cam Tu Luong, Jirí Šesták
Rok vydání:	2009
Předmět:	Fluid Flow and Transfer Processes Pressure drop Plug flow Materials science Mechanical Engineering Heat transfer enhancement Thermodynamics Laminar flow Mechanics Heat transfer coefficient Condensed Matter Physics Open-channel flow Heat transfer Micro-loop heat pipe
Zdroj:	Heat Transfer Engineering. 30:952-960
ISSN:	1521-0537 0145-7632
Popis:	Flow inversion, transferring a liquid from the wall region toward the center of the pipe or from the axis toward the heat transfer surface, improves heat transfer in the laminar flow regime. While a fully developed velocity profile is quickly established, a thin thermal boundary layer is preserved for a considerable distance in the pipe behind the flow inverter for highly viscous liquids. Thus the pressure drop is increased only locally (by the inverter itself), while heat transfer enhancement is also seen in a long straight section of the pipe. Two original flow inverter designs were tested in a long pipe (3 m in length) heated by condensing steam, using starch molasses as a working medium. Experiments carried out in the range of Reynolds number 4–60 and Graetz number 150–700 resulted in an increase of 20–35% in the heat transfer coefficient, accompanied by a 30–40% increase in the pressure drop. The experimental results confirm the numerical model prediction (within an extended Reynolds number range sta...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::2bef350882f1afb6742e2e1eee4fe3f9 https://doi.org/10.1080/01457630902837434 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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