Mesures locales et globales du frottement dans des microcanaux

Local and global measurements of friction coefficient in microchannels

¹ Laboratoire des Ecoulements Géophysiques et Industriels (LEGI), Equipe Transferts de Chaleur et de Matière, INPG, UJF, CNRS, BP 53, 38041 Grenoble Cedex 09, France
² Centre de Recherche sur les Très Basses Températures (CRTBT), CNRS BP 166, 38042 Grenoble Cedex 09, France

Abstract

Experiments were performed in 2-D microchannels of varying height from 1 mm to 100 µm. For smooth surfaces of the channels, the results did not demonstrate any scale effect. On the contrary, roughness hass been found ta have large effects on the laminar regime of microflows. In that case, friction factor results are consistently higher than values predicted by macroscale correlations but exhibit a classical trend Po vs Re. For microchannels of height below 100 µm we have developed microfabricated systems devoted to local pressure measurements and we have successfully tested silicon strain gauges.