Experimental investigation of two-phase gas-liquid flow in microchannel with T-junction

German Bartkus,Vladimir Kuznetsov,Igor Kozulin,D Markovich,D Zaitsev,A Semenov

doi:10.1051/epjconf/201715900004

German Bartkus, Vladimir Kuznetsov + Show 4 more

Open Access

https://doi.org/10.1051/epjconf/201715900004

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Abstract

Using high-speed video recording and the method of dual laser scanning the gas-liquid flow was investigated in rectangular microchannels with an aspect ratio of 2.35 and 1.26. Experiments were earned out for the vertical flow of ethanol-nitrogen mixture in a microchannel with a cross section of 553×235 µm and for the horizontal flow of water-nitrogen mixture in a microchannel with a cross section of 315×250 µm. The T-mixer was used at the channel's inlet for gas-liquid flow formation. It was observed that elongated bubble, transition, and annular flows are the main regimes for a microchannel with a hydraulic diameter substantially less than the capillary constant. Using laser scanning, the maps of flow regimes for ethanol-nitrogen and water–nitrogen mixtures were obtained and discussed.

Highlights

Multiphase microsystems based on microchannels are perspective for a variety of applications
The study of gas-liquid flow regimes was conducted using the method of dual laser scanning, see Figure 1 (b)
A fragment of the signal from the photodiode for transition flow is shown in Fig. 2 (c) The visualization of the flow is presented in Fig. 2 (d)

Summary

Introduction

Multiphase microsystems based on microchannels are perspective for a variety of applications. Research of gas-liquid flows in microchannels show that it is possible to distinguish 5 basic modes: isolated bubbles, the Taylor bubbles, slug-annular flow, annular and dispersion flow, which properties have been well studied [1, 2]. Important parameters for optimizing the heat and mass transfer processes in microchannels are the bubble length, the liquid film thickness, and their distribution. In the paper [3], the modes of gas-liquid flow in a microchannel with a gap of 300 μm and width from 10 to 30 mm were presented. Laser scanning method was used in [4, 5] for determination of the statistical characteristics of the gas-liquid flows. The objective of the present work is experimental studying the mechanism of multiscale upward vertical and horizontal gas-liquid flow formation in rectangular microchannels of the microfluidic devices. Ethanol, and nitrogen were used as working fluids

Experimental equipment and methods

Two-phase gas-liquid flow in microchannels

Flow pattern maps