Bias Effects on Heat transfer Measurements in Microchannel Flows

Roland Bavière (1, 2) , Michel Favre-Marinet (1) , Stéphane Le Person (1)

1 LEGI - Laboratoire des Écoulements Géophysiques et Industriels [Grenoble]
2 CRTBT - Centre de Recherches sur les Très Basses Températures

This work is devoted to both experimental and numerical investigations of the hydrodynamics and associated heat transfer in two-dimensional microchannels from 700 μm to 200 μm in height. The design of the test section enabled to vary the channel height and to set a quasi-constant heat flux at the microchannel surface. Laminar developing, transitional and turbulent regimes of water flows were explored (200 < Re < 8000). A significant decrease in the Nusselt number was observed in the laminar regime when the channel spacing was decreased while the Poiseuille number remained unchanged in regard to conventional channel flow. It is shown that a bias effect in the solid/fluid interface temperature measurements is most likely responsible for this scale effect. The temperature error was estimated and accounted for in the determination of the Nusselt number. The corrected values have been found to be consistent with the conventional laws both in the laminar and in the beginning of the turbulent regime.

Mots clés: Microheat transfer; Microchannel; Temperature measurements

Domaines: Mécanique des fluides [physics.class-ph]; Thermique [physics.class-ph]

Roland Bavière, Michel Favre-Marinet, Stéphane Le Person. Bias Effects on Heat transfer Measurements in Microchannel Flows. International Journal of Heat and Mass Transfer, 2006, 49 (19-20), pp.3325-3337. ⟨10.1016/j.ijheatmasstransfer.2006.03.014⟩. ⟨hal-00204666⟩