Intermittent air invasion in pervaporating compliant microchannels

Intermittent heat instabilities in an air plume

We report the results of heating experiments carried in an abandoned limestone quarry close to Paris, in an isolated room of a volume of about 400 m. A heat source made of a metallic resistor of power 100 W was installed on the floor of the room, at distance from the walls. High quality temperature sensors, with a response time of 20 s, were fixed on a 2-m long bar. In a series of 24-hour heati...

Pattern formation of flames in radial microchannels with lean methane-air mixtures.

Premixed methane-air mixture is introduced at the center of two parallel circular quartz plates separated by a millimeter scale distance (<or= 5mm). Two plates are heated with an external heater to create a positive temperature gradient condition along the flow direction. The combustion characteristics of lean methane-air mixtures are investigated at phi=0.67 and phi=0.85 in the laminar flow re...

Ledinegg instability in microchannels

The static Ledinegg instability in horizontal microchannels under different flow conditions and fluids pertinent to electronics cooling was studied experimentally and numerically. Two fluids, water at sub-atmospheric pressures and refrigerant HFE-7100, were examined for a range of heat fluxes, mass fluxes, and channel hydraulic diameters. Numerical predictions from the developed pressure gradie...

Optofluidic microchannels in aerogel.

We report optofluidic waveguides made by filling microchannels in aerogel with water. The aerogel cladding is a nanoporous material with an extremely low refractive index of ~1.05, giving a large index step from the water core. Channels were formed by removing embedded optical fibers, which could be nonuniform or multiple. The porosity of the aerogel allowed air to be displaced from the channel...

Fluid Dynamics in Microchannels