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Journal ArticleDOI

Pressure losses in two-phase gas-non-newtonian liquid flow in a vertical tube

15 May 1995-Chemical Engineering Communications (Taylor & Francis Group)-Vol. 135, Iss: 1, pp 229-237
TL;DR: Experimental data on pressure drop for two-phase gas-non-Newtonian liquid vertical slug flow have been analyzed in this article, where correlation has been proposed for predicting the twophase friction factor as a function of the physical and dynamic variables of the system.
Abstract: Experimental data on pressure drop for two-phase gas-non-Newtonian ps:udoplastic liquid vertical slug flow have been analysed. Correlation have been proposed for predicting the two-phase friction factor as a function of the physical and dynamic variables of the system.
Citations
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Journal ArticleDOI
TL;DR: In this article, the authors presented data on the total two-phase pressure drop for air-water vertical flow in a 0.026m i.d. pipe, showing that the data exhibit a maximum value, at the end of the churn flow regime, set between two minima at the beginning of the slug and annular ripple regimes respectively.
Abstract: Data are presented on the total two-phase pressure drop for air-water vertical flow in a 0.026m i.d. pipe. The data exhibit a maximum value, at the end of the churn flow regime, set between two minima at the end of the slug and annular ripple regimes respectively. There was a noticeable diameter effect. It was possible to explain the form of the pressure loss data qualitatively. In the slug and allied regimes the rising gas bubble carried a pocket of liquid in its wake resulting in a reduction in the fluid head. None of the current theories of pressure loss prediction proved to be useful. However, it was possible to predict bubble flow at low gas rates and annular droplet flow at high gas rates.

39 citations

Dissertation
01 Jan 2010
TL;DR: Ratkovich et al. as mentioned in this paper studied the behavior of three different liquid-gas slug flows (water, carboxymethyl cellulose and activated sludge) in a vertical tube using a high speed camera.
Abstract: The behaviour of three different liquid-gas slug flows (water, carboxymethyl cellulose and activated sludge) in a vertical tube was studied using a High Speed Camera (HSC). Experiments were performed using different nitrogen gas and liquid flow rates and two tube diameters (6.3 and 9.9 mm). The observed difference in behaviour of the ascending gas slugs can be explained by the difference in viscosity of the fluids (Newtonian and nonNewtonian). Moreover, it was observed that the degree of coalescence of gas slugs is lower for non-Newtonian liquids and they behave like a succession of slugs without actually coalescing into a single larger gas slug. Finally, gas slug rising velocities were extracted, but no subsequent difference in the rising velocities of the different fluids was found. * Redrafted after: Ratkovich, N., Chan, C.C.V., Berube, P., Nopens, I. Investigation of the effect of viscosity on slug flow in airlift tubular membranes in search for a sludge surrogate. Water Science and Technology (in press)

10 citations


Cites background or methods from "Pressure losses in two-phase gas-no..."

  • ...Instead, to determine the frictional pressure drop for gas and non-Newtonian liquid two-phase flow (Biswas and Das, 2008; Das and Biswas, 1995) the following can be used:...

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  • ...where the friction factor for gas and non-Newtonian liquid two-phase flow is defined by (Das and Biswas, 1995):...

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  • ...…can be used: d u u uL fP SL SG SLL tpfrict + =∆ 1 2 2ρ (1.56) where the friction factor for gas and non-Newtonian liquid two-phase flow is defined by (Das and Biswas, 1995): 3328.08291.1 6102.02231.3 LPMR SG tp NRe Re f = (1.57) where SGRe is determined using equation (1.10) using the…...

    [...]

  • ...Instead, to determine the frictional pressure drop for gas and non-Newtonian liquid two-phase flow (Biswas and Das, 2008; Das and Biswas, 1995) the following can be used: d u u uL fP SL SG SLL tpfrict + =∆ 1 2 2ρ (1.56) where the friction factor for gas and non-Newtonian liquid two-phase flow…...

    [...]

Journal ArticleDOI
TL;DR: In this paper, the authors compared the performance of three different multilayer perceptron training algorithms namely Backpropagation, Scaled Conjugate Gradient and Levenberg-Marquardt for the prediction of the gas hold up and frictional pressure drop across the vertical pipe for gas non-Newtonian liquid flow from previous experimental data.
Abstract: This paper is an attempt to compare the the performance of the three different Multilayer Perceptron training algorithms namely Backpropagation, Scaled Conjugate Gradient and Levenberg-Marquardt for the prediction of the gas hold up and frictional pressure drop across the vertical pipe for gas non-Newtonian liquid flow from our earlier experimental data The Multilayer Perceptron consists of a single hidden layer Four different transfer functions were used in the hidden layer All three algorithms were useful to predict the gas holdup and frictional pressure drop across the vertical pipe Statistical analysis using Chi-square test (χ2) confirms that the Backpropagation training algorithm gives the best predictability for both cases

2 citations


Cites background or methods from "Pressure losses in two-phase gas-no..."

  • ...Gas-non-Newtonian liquid flow through vertical tube have been studied and the empirical correlations are developed for the prediction of gas holdup and pressure drop respectively [15, 16]....

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  • ...The experimental data is taken from our earlier work [15, 16]....

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References
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Book
01 Jan 1969

233 citations

Journal ArticleDOI
TL;DR: In this paper, a statistical correlation for holdup was developed to include fluid physical properties, total mass velocity, and the air-liquid ratio entering the pipe, which showed an average percentage error of less than 15% between the observed and the calculated total pressure drop.
Abstract: Vertical upward concurrent air-liquid flow was investigated under isothermal conditions in a test section of 1-in. schedule 40 pipe. Pressure drop was measured with a mercury manometer connected to two pressure taps 20 ft. apart in the section. Liquid was trapped between two quick shutoff valves activated by two solenoid valves. The liquid was druined from the section to provide the holdup data. Six liquids were used to determine the effect of density, viscosity, and surface tension. The experimental holdup, and two-phase pressure drop data were not in agreement with Lockhart-Martinelli type of correlation for horizontal flow. A statistical correlation for holdup was developed to include fluid physical properties, total mass velocity, and the air-liquid ratio entering the pipe. Similarly a pressure drop correlation was developed which expressed the two-phase pressure drop as a function of the slip velocity, liquid physical properties, and total mass velocity. This correlation showed an average percentage error of less than 15% between the observed and the calculated total pressure drop.

72 citations