Mathematical Model for Predicting the Development of Two-Phase Flow in a Horizontal Pipe (original) (raw)
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Industrial & Engineering Chemistry Research, 2010
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Frontiers and Progress in Multiphase Flow I, 2014
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International Journal of Engineering Research and Technology (IJERT), 2016
https://www.ijert.org/an-experimental-study-on-two-phase-air-water-flow-characteristics-in-a-horizontal-pipe-at-atmospheric-conditions https://www.ijert.org/research/an-experimental-study-on-two-phase-air-water-flow-characteristics-in-a-horizontal-pipe-at-atmospheric-conditions-IJERTV5IS010553.pdf This paper outlines an experimental investigation of two phase (air-water) flow characteristics or regimes in a horizontal steel pipe at atmospheric conditions. The two phase flow phenomenon finds application in the chemical, petroleum, nuclear and power industries. The detailed analysis of different flow patterns or flow regimes and void fraction is carried out here. These flow patterns are governed by different physical mechanism; influence the mass, momentum and heat transfer rates and hence results into the complication in the analysis of two phase flow. Based on an investigation made by many researchers, an experimental set up has been fabricated to obtain different flow regimes by varying flow velocity of water and air simultaneously in horizontal test section of a 0.0239 m diameter pipe. In the present study, to identify the flow patterns video graphic evidences are used with high resolutions camera images. The observed flow patterns are are closely agreed with those specified in literature survey which classified as stratified wavy, stratified smooth, elongated bubbly (slug), bubbly flow and annular flow regimes. The physical mechanisms that govern the transition between these regimes are also identified and discussed.
Experimental study on vertical downward air-water two-phase flow in a large diameter pipe
Downward two-phase flows in large diameter pipes are important in various industrial applications, especially for the safety analysis in nuclear reactors. To address the issue that few data of downward flow in large diameter pipes is available for model evaluation, experiments of air–water downward flow in a pipe with inner diameter of 203.2 mm have been performed. Area-averaged void fraction and pressure measurement, as well as flow visualization, have been conducted at several axial locations. The flow conditions for superficial gas velocity range from 0.05 m/s to 3.00 m/s and for superficial liquid velocity range from 0.1 m/s to 1.5 m/s, which cover cap-bubbly flow, churn-turbulent flow and annular/falling film flow. The flow structure at several axial locations and the transition from churn-turbulent flow to annular/falling film flow have been discussed. Current available drift-flux models developed for downward flow in regular pipes as well as for upward flow in large pipes are evaluated using newly collected data. For churn-turbulent flow, the data indicates a larger drift velocity than the model prediction. Corresponding drift-flux constitutive equations are suggested which can reduce the prediction error from 34.37% to 11.79%.