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Properties of used liquids
Source publication
Using high-speed video recording and the method of dual laser
scanning the gas-liquid flow was investigated in a rectangular
microchannel with an aspect ratio of 0.74 (cross section 269×362 μm). The T-mixer was used at the channel’s inlet for the two-phase flow formation. The peculiarity of this work is using a number of liquids (ethanol, distilled...
Context in source publication
Citations
... The rectangular geometry of microchannels with a high aspect ratio is more preferential now for cooling the equipment and in chemical engineering. At that, there are not so many works involved in the investigation of flow characteristics [2] in microchannels with large aspect ratios [3][4][5]. One of the most important and complex two-phase flow regimes in rectangular microchannels is annular flow, which is often used in many industrial applications. ...
The aim of this work is an experimental study of a gas-liquid flow in a rectangular slit microchannel with a cross-section of 200 × 2045 μm. Ethanol/water (95/5) mixture and nitrogen are used as working liquid and gas, accordingly. The external T-mixer is used for obtaining of wavy-annular flow pattern. The experimental data on interfacial waves and their characteristics in the meniscus area on the short side of the microchannel are obtained using high-speed visualization for a wide range of gas and liquid superficial velocities. Images are processed using the Python libraries to define the average liquid layer thickness and maximum amplitude of waves. An increase of gas superficial velocity causes decreasing in the average liquid layer thickness and maximal amplitude of the liquid layer thickness. The waves on the liquid layer surface (maximal amplitude) can be three times larger than the average liquid layer thickness for presented liquid and gas velocities. With increasing gas superficial velocities more liquid displace from the meniscus area to the liquid film on the wide side of the microchannel.
... The hydrodynamics of gas-liquid and liquid-liquid flows in microchannels was studied in several works in which defined the main flow patterns, e.g. [4][5][6][7]. The present work aims at defining the main flow regimes for gas-liquid flow in the rectangular hydrophilic microchannel with cross-flow T-mixer and obtaining the flow local characteristics including the liquid film thickness, which are necessary for heat and mass transfer prediction. ...
This paper aims at experimental study of gas-liquid flow in a horizontal rectangular hydrophilic microchannel with a cross-section of 200×400 μm. The ethanol and nitrogen are used as working liquids and gas accordingly in the microchannel with crossflow T-mixer at the channel inlet. Experimental data are obtained using high-speed visualization, laser flow scanning, and LIF method. The elongated bubble flow and transition flow are observed in the hydrophilic rectangular microchannel depending on gas and liquid flow rates. Using the LIF method, the non-uniform liquid film distribution is observed in the channel cross-section. The liquid film thickness is measured for elongated bubble flow and transition flow and compared with the Taylor law.
... The hydrodynamics of gasliquid and liquid-liquid flows in microchannels was studied in a number of works in which the main flow patterns were defined, e.g. [5,[7][8][9]. In paper [10] local characteristics of the flows (such as liquid distribution in microchannel) were investigated. ...
... This method is very useful for determining statistical characteristics of two-phase flow, e.g. [9]. The first laser is located at a distance of 6 cm from the T-junction mixer, while camera -at 17.7 cm, and second laser -at 22.4 cm for observing the stable gas-liquid flow. ...
The local characteristics of the gas-liquid two-phase flow in rectangular microchannels 420 × 280 μm and 395 × 205 μm with T-shaped mixer inlet were experimentally investigated in this work. Visualization of flow regimes and measurement of local characteristics were carried out using a high-speed video camera Optronis CX600x2 and laser-induced fluorescence (LIF) method. Deionized water and ethanol were used as the liquid phase, and nitrogen - as the gas phase. The Rhodamine 6G dye was added to the liquid. The location of the microchannel in space (horizontal, vertical) was changed. The profiles of the liquid film along the long side of the microchannel were obtained, the local film thickness was measured in the channel`s central section for the elongated bubble flow and the transition flow of the deionized water-nitrogen mixture. The unevenness of liquid film thickness at the channel cross-section and along the bubble was experimentally shown. The temporal dynamics of two-phase flow for the ethanol-nitrogen mixture was shown. It was found that most of the liquid flows in the meniscus on the short side of the microchannel for the present gas and liquid flow rates.
