Experimental study of dispersed flows in microchannels for 3D printing of composite materials
A.V. Kovalev1,2, A.A. Yagodnitsyna1,2, A.V. Bilskiy1
1Kutateladze Institute of Thermophysics SB RAS, Novosibirsk,Russia
2Novosibirsk State University, Novosibirsk,Russia
Keywords: microchannels, two-phase flows, plug flow mode, microdroplets, 3D printing
Abstract
The paper studies the segmented flow modes of immiscible liquids in microchannels with T- and X-shaped inputs for 3D printing technologies. On the basis of the flow visualization results, mode maps with a distinguished area of stable plug flow are constructed. A fair coincidence of the maps built on the basis on the superficial flow velocities is revealed, and the influence of the channel input on the boundaries of flow modes is shown to be insignificant. When using a less viscous carrier phase, the region of a stable plug mode is demonstrated to expand towards higher superficial flow velocities. The separation of microdrops from the trailing edges of plugs is investigated. It has been found that the transition to the separation of microdrops is described in terms of the capillarity number, constructed from the bulk velocity of the phases, and the ratio of phase flow rates. Thus, a range of dimensionless parameters of microchannel devices, suitable for 3D printing of composite materials with specified properties has been determined.
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