Gas-liquid two-phase flows in minichannels and microchannels display a unique flow pattern called ring film flow, in which stable waves of relatively large amplitudes appear at seemingly regular intervals and propagate in the flow direction. In the present work, the velocity characteristics of gas slugs, ring films, and their features such as the gas slug length, flow phenomena and frictional pressure drop for nitrogen-distilled water and nitrogen-30 wt% ethanol water solution have been investigated experimentally. Four kinds of circular microchannels with diameters of 100 μm, 150 μm, 250 μm and 518 μm were used. The effects of tube diameter and physical properties, especially the surface tension and liquid viscosity, on the flow patterns, gas slug length and the two-phase frictional pressure drop have been investigated by using a high speed camera at 6,000 frames per second. The flow characteristics of gas slugs, liquid slugs and the waves of ring film are presented in this paper.

Volume Subject Area:
Fundamentals of Thermal and Fluid Transport in Nano, Micro, and Mini Scales
Topics:
Flow (Dynamics), Microchannels, Two-phase flow, Slug flows, Nitrogen, Pressure drop, Water, Waves, Ethanol, Film flow, Surface tension, Viscosity
This content is only available via PDF.
Copyright © 2015 by ASME
You do not currently have access to this content.