Microtube liquid single-phase heat transfer in laminar flow

摘要: One of the main applications microscale flow is miniature, high-efficiency heat transfer. The most simple and immediate solution to problem concentrated exchange use small diameter channels with single-phase water flow, but there a lack publicised knowledge about transfer performance in these conditions. In this article, an experimental investigation reported accurately characterize diabatic behaviour laminar circular microducts, ranging from 528 down 120 lm. experiments on capillary 50 lm ID proved upon analysis be unaccountable due intrinsic error contained set-up, which tied large inertia pipe wall, etc. proportion passage at diameter. vacuum environment were carried out ensured test section free convective losses, so that measurements are provided as precise possible within geometry microchannel. occurrence scaling effects such axial conduction walls, viscous heating fluid thermal entrance length was studied criteria established have been validated by measurements. Results show decrease Nusselt number decreasing diameter, dependence linked also Reynolds number, whence conductive losses can deduced, not necessarily restricted redistribution flux wall only.