Experimental Investigation on Wave Initiation and Slugging of Air-Water Stratified Flow in Horizontal Duct

Ansari, Mohammad Reza; Nariai, Hideki

doi:10.1080/18811248.1989.9734367

Cited by 48 publications

(7 citation statements)

References 18 publications

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“…In general, a stratified flow is observed in this downward pipe, in accordance with a flow regime map of Spedding and Nguyen [35] and a similar experimental setup of Vieiro et al [30]. This stratified flow promotes the occurrence of hydrodynamic slug flow driven by the gas-liquid interface instabilities typically taken as conditions for the slug initiation in the experiments [36,37] and numerical simulations [38,39].…”

Section: Experimental Backgroundsupporting

confidence: 86%

Experimental Measurement of Large-Amplitude Intermittent Vibrations of an Inclined Bendable Riser Transporting Unsteady Multiphase Flows

Srinil

Zhu

et al. 2021

Applied Ocean Research

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Section: Experimental Backgroundsupporting

confidence: 86%

Experimental Measurement of Large-Amplitude Intermittent Vibrations of an Inclined Bendable Riser Transporting Unsteady Multiphase Flows

Srinil

Zhu

et al. 2021

Applied Ocean Research

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“…Instabilities can appear and evolve along such interfaces [4,5]. For example, the Kelvin-Helmholtz instability develops along a sheared interface, and grows at a distinct wavelength that has been predicted theoretically [6,7], and confirmed experimentally [8]. Kelvin-Helmholtz instabilities can appear for example on a surface of water below a flow of air [5,9].…”

Section: Introductionmentioning

confidence: 58%

Role of convective acceleration in the interfacial instability of liquid-gas coaxial jets

et al. 2021

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Interfacial instabilities play a major role in breakup events in turbulent multiphase flow. Their role has been clearly identified for two-fluid atomization, and is of paramount importance in spray formation. In planar geometries, Kelvin-Helmholtz instabilities are the main mechanism of creation of a two-phase mixing layer, and information such as wavelengths and frequencies is available in the literature. In cylindrical geometries, the instabilities quickly become three-dimensional and thorough characterization is lacking, despite a wide range of applications using coaxial atomization. We conduct an experimental study of how the interfacial instabilities of a liquid jet surrounded by a turbulent gas co-flow accelerate and develop, before break-up and spray formation. We use high-speed shadowgraphy over a wide range of gas Reynolds numbers to compute the velocity of interfacial perturbations, using Lagrangian tracking, followed by a Eulerian conditioning to obtain local statistics. We identified two regimes of the gradient of the longitudinal mean velocity as a function of the gas Reynolds number: a quadratic scaling at low gas Reynolds numbers and a linear scaling at higher gas Reynolds number. In contrast, the transverse velocity gradients show a linear scaling with gas Reynolds number throughout the studied range.

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“…Ansari and Nariai [9] developed an experimental facility to analyse the wave growth and onset of slugging. They concluded that before slug formation, another wave mechanism happens that includes a few waves with short wavelengths.…”

Section: Introductionmentioning

confidence: 99%

Experimental visualization of two-phase flow patterns and transition from stratified to slug flow

Vaze

Banerjee

2010

Proceedings of the Institution of Mechanical Engineers, Part C:

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The transition from stratified to slug flow generates oscillations in pressure and flowrates. Large liquid surges associated with slug flow are detrimental to the operation of process equipments involving two-phase flow. The characterization of two-phase flow regimes and their transition is thus an important area of research. In the present work, flow patterns for various regimes of air-water two-phase flow are captured experimentally. A flow pattern map is established based on the visualized images. The developed flow regime map is compared with that obtained by Ghajar and Tang. Slug frequency is recorded for a variety of superficial Reynolds number to show the instances of impact pressure. The development of slug and transition to slug flow from stratified flow are analysed using these captured images. It is observed that slug becomes highly chaotic with dispersion of air bubbles, when gas superficial Reynolds number is increased for a fixed value of liquid superficial Reynolds number. For lower gas superficial Reynolds number, the slug is observed to be very clear (without air entrainment). This is true for higher value of liquid superficial Reynolds number as well. The air entrainment increases with increasing gas superficial Reynolds number. This air entrainment might play a dominant role in deciding the flow and thermal characteristics of such two-phase flows.

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Experimental Investigation on Wave Initiation and Slugging of Air-Water Stratified Flow in Horizontal Duct

Cited by 48 publications

References 18 publications

Experimental Measurement of Large-Amplitude Intermittent Vibrations of an Inclined Bendable Riser Transporting Unsteady Multiphase Flows

Experimental Measurement of Large-Amplitude Intermittent Vibrations of an Inclined Bendable Riser Transporting Unsteady Multiphase Flows

Role of convective acceleration in the interfacial instability of liquid-gas coaxial jets

Experimental visualization of two-phase flow patterns and transition from stratified to slug flow

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