Microchannels with substantial friction reduction at large pressure and large flow
2009 (English)In: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems, 2009, no MEMS, 39-42 p.Conference paper (Refereed)
This paper introduces and experimentally verifies a self-regulating method for reducing the friction losses in large microchannels at high liquid pressures and large liquid flows, overcoming limitations with regard to sustainable liquid pressure on a superhydrophobic surface. Our design of the superhydrophobic channel creates an automatic adjustment of the gas pressure in the lubricating air layer to the local liquid pressure in the channel. This is achieved by pneumatically connecting the liquid in the microchannel to the air pockets trapped at channel wall trough a pressure feedback channel. When liquid enters the feedback channel it compresses the air and increases the pressure in the air pocket. This reduces the pressure drop over the air-liquid interface and increases the maximum sustainable liquid pressure. We define a dimensionless fluidic number, WF = PLDh/ ?cos?C, which expresses the fluidic energy carrying capacity of a superhydrophobic microchannel. We experimentally verified that our geometry can sustain several times higher liquid pressure before collapsing, and we measured better friction reducing properties at higher WF values than in previous works. This method could be applicable for reducing near-wall laminar friction in both micro-and macroscale flows.
Place, publisher, year, edition, pages
2009. no MEMS, 39-42 p.
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-25366DOI: 10.1109/MEMSYS.2009.4805313ISI: 000341431500010ScopusID: 2-s2.0-65949121418OAI: oai:DiVA.org:kth-25366DiVA: diva2:357876
IEEE 22nd International Conference on Micro Electro Mechanical Systems
QC 201010202010-10-202010-10-192015-06-10Bibliographically approved