Influence of a sudden expansion on slug flow characteristics in a horizontal two-phase flow: a pressure drop fluctuations analysis

Arabi, Abderraouf; Salhi, Yacine; Si‐Ahmed, El‐Khider; Legrand, Jack

doi:10.1007/s11012-018-0892-5

Cited by 22 publications

(17 citation statements)

References 43 publications

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“…The presence of a very small amount of air bubbles inside the liquid slug was also noted. These two observations confirmed the plug flow [11,13,34,35]. This intermittent flow sub-regime appeared at low superficial gas velocities [13,36].…”

Section: Visual Observationssupporting

confidence: 75%

“…As reported in Section 3.1, an increase in the liquid superficial velocity leads to the onset of intermittent flow, resulting in the appearance of peaks in the pressure drop signals (Fig. 10b) [13,14,34]. We note the low number of slugs (1 in this case) flowing during a period of 20 s. This feature is typical of the onset of intermittent flow sub-regime.…”

Section: Pressure Drop Signal Analysissupporting

confidence: 73%

“…The passage of waves between the pressure taps was also recorded. Meanwhile, the wave generates fewer fluctuations, compared to liquid slugs [34]. Figure 10d shows the signal collected in the case of a highly aerated slug following a pseudo-slug.…”

Section: Pressure Drop Signal Analysismentioning

confidence: 99%

“…As recommended by Arabi et al [13], the values of slug frequency were extracted from the dominant frequency obtained by applying the Power Spectral Density (PSD) on the pressure drop time signal. The detail of this method was given by Arabi et al [13,34]. The obtained slug frequencies are depicted in Figure 11 using the gas based Strouhal number (St G ) (Eq.…”

Section: Slug Frequencymentioning

confidence: 99%

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Onset of intermittent flow: Visualization of flow structures

Arabi

Salhi

Bouderbal

et al. 2021

Oil Gas Sci. Technol. – Rev. IFP Energies nouvelles

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The transition from stratified to intermittent air-water two-phase flow was investigated experimentally, by flow visualization and pressure drop signals analyses, in a 30 mm ID pipe. The intermittent flow’s onset was found to be mainly dependent on the liquid superficial velocity and the pipe diameter. Plug flow, Less Aerated Slug (LAS) or Highly Aerated Slug (HAS) flows could be obtained on the gas superficial velocity grounds. The available models, compared to experiments, could not predict adequately the intermittent flow onset. The appearance of liquid slugs was revealed by peaks in the pressure drop signal. Furthermore, it was shown that the available slug frequency correlations were not valid in the zone of the onset of intermittent flow.

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Section: Visual Observationssupporting

confidence: 75%

Section: Pressure Drop Signal Analysissupporting

confidence: 73%

Section: Pressure Drop Signal Analysismentioning

confidence: 99%

Section: Slug Frequencymentioning

confidence: 99%

See 2 more Smart Citations

Onset of intermittent flow: Visualization of flow structures

Arabi

Salhi

Bouderbal

et al. 2021

Oil Gas Sci. Technol. – Rev. IFP Energies nouvelles

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“…The experimental values of contraction and expansion coefficients are found to be lower for oil-water as compared to only single-phase fluid water flow for other conditions being identical. Experimental studies of the pressure drop for a two-phase slug flow in a horizontal channel with a sudden expansion were carried out in work [8]. An electrochemical method was used to measure the wall shear stress.…”

Section: Introductionmentioning

confidence: 99%

The Effect of a Backward-Facing Step on Flow and Heat Transfer in a Polydispersed Upward Bubbly Duct Flow

Bogatko

Chinak

Evdokimenko

et al. 2021

Water

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The experimental and numerical results on the flow structure and heat transfer in a bubbly polydispersed upward duct flow in a backward-facing step are presented. Measurements of the carrier fluid phase velocity and gas bubbles motion are carried out using the PIV/PLIF system. The set of RANS equations is used for modeling the two-phase bubbly flow. Turbulence of the carrier fluid phase is predicted using the Reynolds stress model. The effect of bubble addition on the mean and turbulent flow structure is taken into account. The motion and heat transfer in a dispersed phase is modeled using the Eulerian approach taking into account bubble break-up and coalescence. The method of delta-functions is employed for simulation of distributions of polydispersed gas bubbles. Small bubbles are presented over the entire duct cross-section and the larger bubbles mainly observed in the shear mixing layer and flow core. The recirculation length in the two-phase bubbly flow is up to two times shorter than in the single-phase flow. The position of the heat transfer maximum is located after the reattachment point. The effect of the gas volumetric flow rate ratios on the flow patterns and maximal value of heat transfer in the two-phase flow is studied numerically. The addition of air bubbles results in a significant increase in heat transfer (up to 75%).

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