Drag reduction experiments with very large pipes

Interthal, W.; Wilski, H.

doi:10.1007/bf01415508

Cited by 32 publications

(13 citation statements)

References 16 publications

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“…Two-component LDV measurements were conducted by many researchers. [17][18][19][20][21] All these experiments confirmed that the root mean square of the velocity fluctuations in the streamwise direction increases while the rms of the fluctuations in the wall-normal direction decreases with DR, and the Reynolds shear stress decreases in the drag-reducing flows. The sum of Reynolds shear stress and viscous shear stresses is lower than the total shear stress without the presence of polymer agents.…”

Section: Introductionsupporting

confidence: 56%

Modeling of viscoelastic turbulent flow in channel and pipe

Yang

Dou

2008

Physics of Fluids

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This paper investigates turbulent flows with or without polymer additives in open channels and pipes. Equations of mean velocity, root mean square of velocity fluctuations, and energy spectrum are derived, in which the shear stress deficit model is used and the non-Newtonian properties are represented by the viscoelasticity ␣ * . The obtained results show that, with ␣ * increment, ͑1͒ the streamwise velocity fluctuations is increased, ͑2͒ the wall-normal velocity fluctuation is attenuated, ͑3͒ the Reynolds stress is reduced, and ͑4͒ there is a redistribution of energy from high frequencies to the low frequencies for the streamwise component, but dimensionless distribution over all frequencies almost remains the same as that in Newtonian fluid flows. Good agreement between the derived equations and experimental data in small drag-reduction regime is achieved, which indicates that the present model is workable for Newtonian/non-Newtonian fluid turbulent flows.

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Section: Introductionsupporting

confidence: 56%

Modeling of viscoelastic turbulent flow in channel and pipe

Yang

Dou

2008

Physics of Fluids

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“…At low concentrations in straight pipe flows, DRPs show asymptotic DR immediately after transition from laminar to turbulent flow regime [93]. It has been reported that the presence of dissolved salts in solution reduces the effectiveness of the DRA in both straight pipes and curves [9,94]. Also adding starch to polymers is reported to have little or no effect on the frictional losses in curved pipes [9].…”

Section: Effect Of Pipe Diametermentioning

confidence: 99%

Drag Reduction by Additives in Curved Pipes for Single-Phase Liquid and Two-Phase Flows: A Review

Ayegba¹,

Edomwonyi‐Otu²,

Abubakar³

et al. 2020

Preprint

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A review of influence of drag-reducing agents on curved pipe flows is presented in this work. In addition, this review outlined proposed mechanism, friction factor and fluid flux models for drag-reducing agents in curved pipe flows. Our finding reveals that drag reduction by additives in curved pipes is quite significant but generally lower than the corresponding drag reduction in straight pipes. It decreases with increase in curvature ratio and more pronounced in the transition and turbulent flow regimes. Drag reduction strongly depends on the polymers and surfactants' concentrations as well as the bubble fraction of micro-bubbles. It is also reported that drag reduction in curved pipes depends on temperature and existence of dissolved salts in the fluids. Maximum drag reduction asymptote differed between straight and curved pipes and between polymer and surfactant. No definite conclusion could be drawn as regards drag reduction for two-phase flow in curved pipes due to the limited studies in this area. Many questions such as the mechanism of drag reduction in curved pipes and how drag-reducing agents interact with secondary flows still remained unanswered. Hence, some research gaps have been identified with recommendations for areas of future researches.

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“…Drag reduction of very dilute solutions has been studied extensively (Virk 1975;McComb and Rabie 1982;Interthal and Wilski 1985;Bird et al 1987;Kulicke et al 1989;Tiu et al 1995Tiu et al , 1996Choi et al 2000;Jovanovic et al 2006), and it can be as high as 80%. These "dilute solutions" are characterized by very small polymer concentrations (several ppm) and a very small viscosification of the water (several %).…”

Section: Drag Reduction Coil/stretch Transition and Polymer Degradamentioning

confidence: 99%

Degradation (or Lack Thereof) and Drag Reduction of HPAM Solutions During Transport in Turbulent Flow in Pipelines

Jouenne¹,

Anfray²,

Cordelier³

et al. 2015

Oil and Gas Facilities

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Rules of thumb that are used in the industry for polymer-flooding projects tend to limit the distance over which hydrolyzed polyacrylamide polymers can be transported in pipelines without undergoing significant degradation. However, in sensitive environments, such as offshore facilities where footprint minimization is required, centralization of the polymer-hydration process and long-distance transport may be desirable. More-reliable rules are required to design the pipe network and to estimate mechanical degradation of polymers during transport in turbulent conditions.In this work, we present evidence in the form of empirical largescale pipeline experiments and theoretical development refuting the claim that polymer pipeline transport is limited by mechanical degradation. Our work concludes that mechanical degradation occurs at a critical velocity, which increases as a function of pipe diameter. Provided the critical velocity is not reached in a given pipe, there is no limit to the distance over which polymer solution can be transported.In addition, the drag reduction of viscous polymer solutions was measured as a function of pipe length, pipe diameter, fluid velocity, and polymer concentration. An envelope was defined to fix the minimum and maximum drag reductions expected for a given velocity in larger pipes. For pipes with diameters varying between 14 and 22 in. at a velocity greater than 1 m/s, the drag-reduction percentage is anticipated to be between 55 and 80%. A morerefined model was developed to predict drag reduction with less uncertainty.In conclusion, classical design rules applied for water transport (fluid velocity < 3 m/s) can be applied to the design of a polymer network. Therefore, for tertiary polymer projects, the existing water-injection network should be compatible with the mechanical requirements of polymer transportation. For secondary polymer projects, changing the rules of design by taking into account the high level of drag reduction should bring some economy to the pipe design and installation.

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Drag reduction experiments with very large pipes

Cited by 32 publications

References 16 publications

Modeling of viscoelastic turbulent flow in channel and pipe

Modeling of viscoelastic turbulent flow in channel and pipe

Drag Reduction by Additives in Curved Pipes for Single-Phase Liquid and Two-Phase Flows: A Review

Degradation (or Lack Thereof) and Drag Reduction of HPAM Solutions During Transport in Turbulent Flow in Pipelines

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