Comparison of local interfacial characteristics between vertical upward and downward two-phase flows using a four-sensor optical probe

Tian, Daogui; Yan, Changqi; Sun, Licheng; Tong, Pan; Liu, Guoqiang

doi:10.1016/j.ijheatmasstransfer.2014.06.025

Cited by 17 publications

(5 citation statements)

References 36 publications

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“…After two years, [18] studied the local interfacial characteristics in upward and downward bubbly flows in 50.8 mm internal diameter pipes by utilizing a four-sensor optical probe in the measurement of local interfacial parameters, including void fraction, interfacial area concentration (IAC), bubble frequency, interfacial velocity, and Sauter mean diameter. They compared the radial profiles of these parameters in the downward flow against those in the upward flow.…”

Section: Gas-liquid Upward and Downward Flowsmentioning

confidence: 99%

Investigating the Behaviour of Air–Water Upward and Downward Flows: Are You Seeing What I Am Seeing?

et al. 2021

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Understanding the behaviour of gas–liquid flows in upward and downward pipe configurations in chemical, petroleum, and nuclear industries is vital when optimal design, operation, production, and safety are of paramount concern. Unfortunately, the information concerning the behaviour of such flows in large pipe diameters is rare. This article aims to bridge that gap by reporting air–water upward and downward flows in 127 mm internal diameter pipes using advanced conductance ring probes located at two measurement locations. The liquid and gas flow rates are 0.021 to 0.33 m/s and 3.52 to 16.1 m/s, correspondingly, covering churn and annular flows. To achieve the desired objectives, several parameters, probability density function (PDF), power spectral density (PSD), Slippage Number (SN), drift velocity (Ugd), and distribution coefficient (C0) were employed. The flow regimes encountered in the two pipe configurations were distinguished employing a flow regime map available in the literature and statistical analysis. The obtained results were supported by visual inspection. The comparison between the present study against reported studies reveals the same tendency for the measured experimental data. The Root Mean Square Error (RMSE) method within 4% was utilized in recommending the best void fraction prediction correlation for the downward and upward flows.

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Section: Gas-liquid Upward and Downward Flowsmentioning

confidence: 99%

Investigating the Behaviour of Air–Water Upward and Downward Flows: Are You Seeing What I Am Seeing?

et al. 2021

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“…By definition, from the volumetric principle method, Therefore, by rearranging equations (14) and (18), the gas volume flow fraction is Replacing the lengths of the no-break and break sections in equation (20) with equations (15) and (17), equation (20) becomes…”

Section: Derivation Of Analytical Solutionsmentioning

confidence: 99%

“…Bhagwat and Ghajar [18] analyzed 1208 and 909 experimental data points for upflow and downflow, respectively, and demonstrated definite variations in the void fractions with varying phase flow rates. Many researchers [19][20][21][22][23][24] have investigated the flow patterns of the twophase upflow and downflow. Most of these studies focused on small diameters less than 100 mm, with the exception of Almabrok et al [24], who conducted an experimental study on gas-water flow behaviors in a vertical pipe with a diameter of 101.6 mm.…”

Section: Introductionmentioning

confidence: 99%

Gas‐water energy conversion efficiency in two‐phase vertical downflow

Sun

Yao

Fan

et al. 2018

Energy Science & Engineering

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An automatic pump is developed using low water-head hydropower. The energy conversion efficiency η of the gas-water energy conversion equipment is the focus. In this equipment, low-head water normally drains to the vertical downcomer. When water particles separate via gravity, a vacuum is generated, and air is mixed into the water spontaneously. High-pressure gas is ultimately produced at the end of the pipe. To discuss the effects of the air intake pipe diameter, river drop and water flow rate on η, a full-scale experiment is conducted, and an analytical solution based on the separation of water particles is derived. The air intake pipe diameter has almost no effect on η, but η changes dramatically as the water flow rate varies. Meanwhile, η initially increases and then decreases as the river drop increases. These findings enable the development of a method for low water-head hydropower utilization. 307

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“…Unfortunately, only cross-sectional averaged void fraction data are provided due to the average measurement technique, and no other interfacial structure parameters information is discussed. Tian et al [27] compared detailed interfacial structures measured with a four-sensor optical probe in upward and downward flows. However, measurements were performed at the 22 pipe diameter location, where the flow was suspected to be undeveloped.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation on Effects of Flow Orientation on Interfacial Structure of Air–Water Two-Phase Flow

Qiao

Ren

et al. 2022

Coatings

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This study focusses on investigating the effect of flow orientation on global and local two-phase flow parameters under two-phase flow conditions. Flow visualization, pressure measurement, and conductivity probe measurements are performed in a test facility made of 50.8 mm inner diameter acrylic pipes with flow visualization, pressure measurement, and conductivity probe measurement. Characteristics of flow regimes and interfacial structures, and frictional pressure drop prediction in the vertical upward and vertical downward two-phase flows are compared and analyzed. The results show that unique coring phenomenon and slug bubbles with off-centered noses appear in the vertical downward flow. The flow regime transition boundaries shift to the lower gas superficial velocities in the vertical downward flow compared to that in the vertical upward flow. Furthermore, the distribution and one-dimensional transport of the void fraction, interfacial area concentration, bubble velocity, bubble Sauter-mean diameter, and bubble frequency are acquired and compared to study the effect of flow orientation on interfacial structures. The interfacial structure and its development are found to be mainly affected by the lift force and the turbulence related bubble interactions. The frictional pressure drop is acquired and modeled by the Lockhart–Martinelli correlation. The frictional pressure drop is found to be larger in the vertical upward flow than that in the vertical downward flow. The recommended C value for both vertical upward and vertical downward flows are proposed.

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Comparison of local interfacial characteristics between vertical upward and downward two-phase flows using a four-sensor optical probe

Cited by 17 publications

References 36 publications

Investigating the Behaviour of Air–Water Upward and Downward Flows: Are You Seeing What I Am Seeing?

Investigating the Behaviour of Air–Water Upward and Downward Flows: Are You Seeing What I Am Seeing?

Gas‐water energy conversion efficiency in two‐phase vertical downflow

Experimental Investigation on Effects of Flow Orientation on Interfacial Structure of Air–Water Two-Phase Flow

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