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Fluid flow in trapezoidal silicon microchannels with 3D random rough bottoms / Renqiang, Xiong in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 3 (Mars 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 3 (Mars 2011) . - 07 p. Titre : Fluid flow in trapezoidal silicon microchannels with 3D random rough bottoms Type de document : texte imprimé Auteurs : Renqiang, Xiong, Auteur Année de publication : 2011 Article en page(s) : 07 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Trapezoidal  microchannel  Random  roughless  Friction  factor Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this paper, a bottom-up approach is used to construct random rough bottom walls for trapezoidal silicon microchannels with hydraulic diameters Dh from 47 µm to 241 µm. The top and side walls are set to be smooth. A computational fluid dynamics solver is used to solve the 3D Navier–Stokes equations for the water flow through the rough trapezoidal microchannels. No-slip and periodic boundary conditions are applied to achieve the fully developed flow characteristics. The effects of Reynolds number Re (75–600), relative roughness height H/Dh (1.66–5.39%), aspect ratio beta (0.13–1), and base angle theta (30–90 deg) on the Poiseuille number Po are investigated. It is found that the roughness strongly affects the flow near the bottom wall but does not have significant effect on the center flow. The Po number in the developing flow region increases with the Re number and in the fully developed region tends to be independent of the Re number. The entrance length Le is found to be smaller than that in smooth channels because the roughness reduces hydraulic diameter Dh of the microchannel. It is also observed that with a certain H/Dh, the Po number has a larger deviation from the theoretical value with a smaller beta, and with the same H/Dh and beta, theta DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...] [article] Fluid flow in trapezoidal silicon microchannels with 3D random rough bottoms [texte imprimé] / Renqiang, Xiong, Auteur . - 2011 . - 07 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 3 (Mars 2011) . - 07 p. Mots-clés : Trapezoidal  microchannel  Random  roughless  Friction  factor Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this paper, a bottom-up approach is used to construct random rough bottom walls for trapezoidal silicon microchannels with hydraulic diameters Dh from 47 µm to 241 µm. The top and side walls are set to be smooth. A computational fluid dynamics solver is used to solve the 3D Navier–Stokes equations for the water flow through the rough trapezoidal microchannels. No-slip and periodic boundary conditions are applied to achieve the fully developed flow characteristics. The effects of Reynolds number Re (75–600), relative roughness height H/Dh (1.66–5.39%), aspect ratio beta (0.13–1), and base angle theta (30–90 deg) on the Poiseuille number Po are investigated. It is found that the roughness strongly affects the flow near the bottom wall but does not have significant effect on the center flow. The Po number in the developing flow region increases with the Re number and in the fully developed region tends to be independent of the Re number. The entrance length Le is found to be smaller than that in smooth channels because the roughness reduces hydraulic diameter Dh of the microchannel. It is also observed that with a certain H/Dh, the Po number has a larger deviation from the theoretical value with a smaller beta, and with the same H/Dh and beta, theta DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...]