Instituto Superior Técnico Center for Innovation, Technology and Policy Research, IN+ Av.Rovisco Pais, 1049-001 Lisbon, Portugal Tel.: + 351 21 841 9724 Fax.: + 351 21 849 6156
Vânia Silvério has a graduation in Technological Chemistry since 2003 and is now a researcher at the Center for Innovation, Technology and Policy Research, IN+, of Instituto Superior Técnico, Technical University of Lisbon, Portugal since June 2006. Vânia’s research focus mainly on the subject of two phase heat transfer mechanisms in micro heat exchangers. She is also interested in InOX thin films, micromachining techniques and nanotechnologies.
Notes: V. Silverio & A. L. N. Moreira (2008) - PRESSURE DROP AND HEAT CONVECTION IN SINGLE-PHASE FULLY-DEVELOPED, LAMINAR FLOW IN MICROCHANNELS OF DIVERSE CROSS-SECTION
Abstract: The paper reports the test of a facility designed to study heat transfer effects in microchannels with constant heat flux, which simultaneously allows optical access for laser based and visualization techniques. The heat power is supplied by Joule effect making use of a transparent thin film of indium oxide (InOx) coated onto the outer surface of channels made of borosilicate glass with hydraulic diameters of 200ïm and 500ïm. The experiments reported here were conducted to evaluate the accuracy of the experimental facility to study single phase fully developed laminar flows but, simultaneously, contribute to critically assess the discrepancies reported in the literature from the laminar theory.
The experiments include measurements of pressure drop and longitudinal temperature variation in the fully developed laminar flows of distilled water and a dielectric fluid at Reynolds numbers up to 800. Deviations from the laminar flow theory were not observed in the hydrodynamic behavior, but noticeable differences are observed in the thermal behavior, though with magnitudes differing for both liquids, thus suggesting the likely influence of the thermophysical properties of the fluid. The film used to heat the fluid showed good chemical stability within temperatures up to 70ºC and, therefore, the observed discrepancies are not attributed to the thermal boundary conditions.
Notes: V. Silverio & A. L. N. Moreira (2008) - Friction losses and heat transfer in laminar microchannel single-phase liquid flow - Proceedings of the Sixth International ASME Conference on Nanochannels, Microchannels and Minichannels, ICNMM2008, June 23-25, 2008, Darmstadt, Germany
