Scale-Up Correlation for the Flow of Surfactant-Based Fluids in Circular Coiled Pipes

2010 ◽  
Vol 132 (8) ◽  
Author(s):  
Ahmed H. Ahmed Kamel ◽  
Subhash N. Shah
Keyword(s):  
Power Law ◽  
Large Scale ◽  
Flow Behavior ◽  
Scale Up ◽  
Deborah Number ◽  
Small Scale ◽  
Power Law Model ◽  
Flow Data ◽  
Coiled Tubing ◽  
Fluid Elasticity

This study involves experimental investigation on the flow properties of aqueous surfactant-based (SB) fluids in small and large-scale coiled tubing. It aims at understanding the viscoelastic properties and its effect on the flow behavior of SB fluids in coiled tubing. In spite of SB fluids wide use as friction reducer and/or fracturing fluid in the oil and gas industry, the flow data in large pipe sizes as well as coiled tubing are very scarce. Majority of the available flow data are gathered in straight pipes with small sizes. The scale-up of small-scale flow data is questionable due to the pronounced diameter effect. Furthermore, previous studies have correlated flow behavior of these fluids only through simple power-law model parameters. Limited work with polymeric fluids has been reported that includes fluid elasticity in scale-up procedure and it is nonexistent for highly elastic SB fluids. In this study, the properties of widely used Aromox APA-T, a highly active surfactant used as gelling agent in aqueous and brine base fluids, are thoroughly investigated. Rheological measurements are conducted using Bohlin rheometer for SB fluid concentration of 1.5 vol %, 2 vol %, 3 vol %, and 4 vol %. Flow data are gathered using 1.27 cm, 3.81 cm, 6.03 cm, and 7.30 cm OD coiled tubing with various curvature ratios. This study presents the first attempt to investigate the flow behavior SB fluids in large-scale coiled tubing. The results show that SB fluids exhibit non-Newtonian pseudoplastic behavior. Elastic and viscous properties of SB fluids are very sensitive to surfactant concentration. Friction losses in coiled tubing are significantly higher than those in straight pipes due to secondary flow effect. Increasing curvature ratio yields higher friction pressure loss. Also, small-scale data correlations using only simple power-law model fluid rheological parameters lead to erroneous results when scaled-up to large pipe sizes. New technique, based on the modified Deborah number, which includes fluid elasticity and pipe shear effect, has been developed to correlate data from the small laboratory-scale tubing and large field-scale pipes. Correlation to predict Fanning friction factor of SB fluids in coiled tubing as a function of Deborah number and fluid flow behavior index is presented. Correlation is validated by comparing predictions with the experimental data. It is shown that the new correlation accurately predicts friction factor of SB fluids and thus alleviates the scale-up issue.

scholarly journals Reversals in the large-scale αΩ-dynamo with memory

2015 ◽  
Vol 22 (4) ◽  
pp. 361-369 ◽  
Author(s):  
L. K. Feschenko ◽  
G. M. Vodinchar
Keyword(s):  
Magnetic Field ◽  
Power Law ◽  
Geomagnetic Field ◽  
Large Scale ◽  
Magnetic Polarity ◽  
Power Law Model ◽  
The Real ◽  
Geomagnetic Polarity ◽  
With Memory ◽  
The Magnetic Field

Abstract. Inversion of the magnetic field in a model of large-scale αΩ-dynamo with α-effect with stochastic memory is under investigation. The model allows us to reproduce the main features of the geomagnetic field reversals. It was established that the polarity intervals in the model are distributed according to the power law. Model magnetic polarity timescale is fractal. Its dimension is consistent with the dimension of the real geomagnetic polarity timescale.

scholarly journals Combined measurement of velocity and temperature in liquid metal convection

2019 ◽  
Vol 876 ◽  
pp. 1108-1128 ◽  
Author(s):  
Till Zürner ◽  
Felix Schindler ◽  
Tobias Vogt ◽  
Sven Eckert ◽  
Jörg Schumacher
Keyword(s):  
Reynolds Number ◽  
Liquid Metal ◽  
Large Scale ◽  
Scale Up ◽  
Convection Cell ◽  
Small Scale ◽  
Convection Flow ◽  
Large Scale Circulation ◽  
Large Scale Flow ◽  
The Impact

Combined measurements of velocity components and temperature in a turbulent Rayleigh–Bénard convection flow at a low Prandtl number of $Pr=0.029$ and Rayleigh numbers of $10^{6}\leqslant Ra\leqslant 6\times 10^{7}$ are conducted in a series of experiments with durations of more than a thousand free-fall time units. Multiple crossing ultrasound beam lines and an array of thermocouples at mid-height allow for a detailed analysis and characterization of the complex three-dimensional dynamics of the single large-scale circulation roll in a cylindrical convection cell of unit aspect ratio which is filled with the liquid metal alloy GaInSn. We measure the internal temporal correlations of the complex large-scale flow and distinguish between short-term oscillations associated with a sloshing motion in the mid-plane as well as varying orientation angles of the velocity close to the top/bottom plates and the slow azimuthal drift of the mean orientation of the roll as a whole that proceeds on a time scale up to a hundred times slower. The coherent large-scale circulation drives a vigorous turbulence in the whole cell that is quantified by direct Reynolds number measurements at different locations in the cell. The velocity increment statistics in the bulk of the cell displays characteristic properties of intermittent small-scale fluid turbulence. We also show that the impact of the symmetry-breaking large-scale flow persists to small-scale velocity fluctuations thus preventing the establishment of fully isotropic turbulence in the cell centre. Reynolds number amplitudes depend sensitively on beam-line position in the cell such that different definitions have to be compared. The global momentum and heat transfer scalings with Rayleigh number are found to agree with those of direct numerical simulations and other laboratory experiments.

scholarly journals Spatial heterogeneity and variability of a large-scale vegetation community using a power-law model

2005 ◽  
Vol 10 (4) ◽  
pp. 469-477 ◽  
Author(s):  
Zhiyuan Song ◽  
Darning Huang ◽  
Masae Shiyomi ◽  
Yusheng Wang ◽  
Shiqeo Takahashi ◽  
...  
Keyword(s):  
Spatial Heterogeneity ◽  
Power Law ◽  
Large Scale ◽  
Power Law Model ◽  
Vegetation Community

Establishment of Testing Methodology for Forge Welded Tubular Products

2012 ◽  
Author(s):  
Ganesan S. Marimuthu ◽  
Per Thomas Moe ◽  
Bjarne Salberg ◽  
Jan Inge Audestad
Keyword(s):  
Material Flow ◽  
Large Scale ◽  
Flow Behavior ◽  
Treatment Options ◽  
Full Scale ◽  
International Standards ◽  
Small Scale ◽  
Test Plan ◽  
Welding Machine

A state-of-the-art small-scale solid state forge welding machine has been fabricated for checking weldability by Shielded Active Gas Forge Welding (SAG-FW) of tubular products applicable predominantly for, but not limited to offshore Industries. Effective, fast and inexpensive welding and testing of joints make this small-scale method suitable for evaluating weldability of a material before starting regular qualification and fabrication in a full-scale welding machine normally located in spool base or offshore. The small-scale machine provides a complete package for pre-qualification studies, including assessment of welding conditions, material flow behavior, heat treatment options. However, there are considerable challenges relating to application of international standards of testing as well as interpretation and use of results in the context of large-scale welding. In this paper results from small-scale welding and weld characterization of an API 5L X65 quality are presented. First, a detailed test plan for analyzing the weld is outlined. This procedure is subsequently applied for checking the welds to be produced in the full-scale machine. Short-comings in using the small-scale process as well as the possible remedies are discussed in detail.

Radial Profiles of Particle Velocity in a Large Scale CFB Downer

2004 ◽  
Vol 2 (1) ◽  
Author(s):  
Zhen Qian ◽  
Minghui Zhang ◽  
Hao Yu ◽  
Fei Wei
Keyword(s):  
Particle Velocity ◽  
Large Scale ◽  
Circulating Fluidized Bed ◽  
Scale Up ◽  
Radial Profile ◽  
Small Scale ◽  
Wall Region ◽  
Radial Profiles ◽  
Peak Value ◽  
Near Wall

Radial profiles of particle velocity in a large scale (418 mm I.D.) downward Circulating Fluidized Bed (CFB downer) were obtained via a Laser Doppler Velocimetry (LDV) system. Results show that particle velocity is gradually increasing along the radial direction and there exists a peak value in the near wall region. Such unique radial profile shape can be explained by the solids accumulating trend in the near wall region of the downer. Experiment results in this large scale downer are also compared with those obtained by other researchers in small scale units so as to investigate the scale-up effect on the radial particle velocity distribution in the downer.

Non-Newtonian Flow Behavior in Microchannels for Emulsion Formation

2006 ◽  
Author(s):  
Ravi Arora ◽  
Eric Daymo ◽  
Anna Lee Tonkovich ◽  
Laura Silva ◽  
Rick Stevenson ◽  
...  
Keyword(s):  
Shear Stress ◽  
Pressure Drop ◽  
Wall Shear Stress ◽  
Power Law ◽  
Flow Behavior ◽  
Scale Up ◽  
High Wall Shear Stress ◽  
Shear Rates ◽  
Wall Shear ◽  
Low Shear

Emulsion formation within microchannels enables smaller mean droplet sizes for new commercial applications such as personal care, medical, and food products among others. When operated at a high flow rate per channel, the resulting emulsion mixture creates a high wall shear stress along the walls of the narrow microchannel. This high fluid-wall shear stress of continuous phase material past a dispersed phase, introduced through a permeable wall, enables the formation of small emulsion droplets — one drop at a time. A challenge to the scale-up of this technology has been to understand the behavior of non-Newtonian fluids under high wall shear stress. A further complication has been the change in fluid properties with composition along the length of the microchannel as the emulsion is formed. Many of the predictive models for non-Newtonian emulsion fluids were derived at low shear rates and have shown excellent agreement between predictions and experiments. The power law relationship for non-Newtonian emulsions obtained at low shear rates breaks down under the high shear environment created by high throughputs in small microchannels. The small dimensions create higher velocity gradients at the wall, resulting in larger apparent viscosity. Extrapolation of the power law obtained in low shear environment may lead to under-predictions of pressure drop in microchannels. This work describes the results of a shear-thinning fluid that generates larger pressure drop in a high-wall shear stress microchannel environment than predicted from traditional correlations.

Large-Scale Rig for the Characterization of DCC at Sub-Atmospheric Pressure

2020 ◽  
Author(s):  
R. Lo Frano ◽  
A. Pesetti ◽  
D. Aquaro ◽  
M. Olcese
Keyword(s):  
Atmospheric Pressure ◽  
Large Scale ◽  
Fusion Reactor ◽  
Scale Up ◽  
Small Scale ◽  
Vacuum Vessel ◽  
Steam Condensation ◽  
Main Components ◽  
Under Construction ◽  
Experimental Rig

Abstract The Direct Contact Condensation (DCC) is the main phenomenon characterizing the steam condensation. It plays an important role for the operation of Vacuum Vessel Pressure Suppression System (VVPSS) tanks, particularly for managing the Ingress of Coolant Event (determining fusion reactor overpressurization). It is safety relevant (key) system of the fusion reactor because by condensing the steam generated during such accident event allows to damp the overpressure. This paper deals with experimental and theoretical analyses of the DCC at sub-atmospheric pressure. The similitude analysis was elaborated to scale up the experimental results obtained in the reduced scale facility: similitude laws are used for the design of large experimental rig. Correlations are defined starting from the water temperature and pressure variation already obtained in the small-scale rig. Furthermore, the experimental rig and its main components accordingly designed (and under construction at the University of Pisa) allow to study at large scale the steam condensation. The testing conditions are presented and discussed.

scholarly journals Scaling the INGO: What the Development and Expansion of Canadian INGOs Tells Us

2020 ◽  
Vol 9 (8) ◽  
pp. 140
Author(s):  
Logan Cochrane ◽  
John-Michael Davis
Keyword(s):  
Large Scale ◽  
Scale Up ◽  
Critical Factor ◽  
Individual Case ◽  
Government Funding ◽  
Future Research ◽  
Small Scale ◽  
Non Governmental Organizations ◽  
Original Dataset ◽  
Organizational Age

The literature on international non-governmental organizations (INGOs) has focused primarily on large INGOs, which capture the majority of total INGO spending but represent a small number of total INGOs. Over the past two decades, the number of INGOs has more than tripled throughout the global North, which has ushered in a decentralization of the sector as an emerging class of small- and medium-sized INGOs increasingly share the same space once occupied solely by large INGOs. This study focuses on these INGOs in transition to explore how they differ from large INGOs that receive significant government funding and their pathways to scale. Using an original dataset of 1371 Canadian INGOs, we explored comparative differences related to funding sources, overhead, organizational age, country coverage, staff, and religion between the transitioning and small-scale INGOs. Our results identified several general insights for how INGOs transition: (1) Large INGOs are less likely to articulate a religious motivation, which may impede government funding; (2) INGOs are more likely to be headquartered in Ontario, which is closer to federal government offices; (3) low overhead expenditures inhibit small-scale INGOs from transitioning to medium- and large-scale INGOs; (4) organizational age plays a critical factor to scale-up as INGOs increase their experience and expertise; (5) generous compensation to attract talented staff offers an under-valued pathway to scale. Finally, our results demonstrate the diversity among INGOs in Canada and problematizes singular scale-up pathways, while underscoring the necessity of future research to explore scaling strategies through individual case studies.

scholarly journals STUDY THE GROWTH KINETICS OF PEDIOCOCCUS ACIDILACTICI WITH ESTIMATION OF KINETIC PARAMETERS AND APPLIED IN LARGE SCALE PEDIOCIN PRODUCTION

2016 ◽  
Vol 9 (5) ◽  
pp. 130
Author(s):  
Barnali Mandal
Keyword(s):  
Experimental Data ◽  
Lactic Acid ◽  
Kinetic Parameters ◽  
Growth Kinetics ◽  
Large Scale ◽  
Scale Up ◽  
Small Scale ◽  
Pediococcus Acidilactici ◽  
Monod Model ◽  
Kinetics Of

ABSTRACTObjectives: The aim of the study was to determine the growth kinetics of Pediococcus acidilactici using a mathematical model for large scale pediocinproduction.Methods: Growth kinetics of P. acidilactici has been studied for pediocin production in small scale batch fermenter (Erlenmeyer flask) using meatprocessing waste medium. The experiments have been conducted with varying the concentrations of glucose, protein, and lactic acid. A mathematicalmodel has been developed to describe growth rate, products (pediocin and lactic acid) formation rate, and substrates (glucose and protein) utilizationrate. Monod model for dual substrates (glucose and protein) has been used with considering lactic acid inhibition. Luedeking-Piret model has beenintroduced to describe the production of pediocin and lactic acid.Results: The values of kinetic parameters have been determined using experimental data and model equations. The model prediction has beencompared satisfactorily with the experimental data for the validation of the model.Conclusions: The developed model was satisfactorily validated to scale up the production of pediocin.Keywords: Pediococcus acidilactici, Pediocin, Meat processing waste, Monod model, Luedeking-Piret model, Kinetic parameters.

Dispersive Mixing Consideration of Twin-Screw Compounding Scale-Up Methodologies

2015 ◽  
Author(s):  
Benjamin Dryer ◽  
Graeme Fukuda ◽  
Jake Webb ◽  
David I. Bigio ◽  
Mark Wetzel ◽  
...  
Keyword(s):  
Material Properties ◽  
Large Scale ◽  
Scale Up ◽  
Polymer Melt ◽  
Operating Conditions ◽  
Small Scale ◽  
Twin Screw ◽  
Industry Practice ◽  
Break Up ◽  
Dispersive Mixing

Twin-screw polymer extrusion has shown increased utility for creating composite materials. However, in order to achieve the desired product properties, sufficient mixing is essential. Dispersive mixing, or the breaking-up of particle agglomerates, is critical to create filled compounds with the required material properties. In a twin-screw compounding process, the Residence Stress Distribution (RSD) has been used to quantify the dispersive mixing induced by the stresses in the polymer melt. These stresses are quantified by the percent break-up of stress-sensitive polymeric beads. It was found that the amount of material that experiences the critical stress is a function of the operating conditions of screw speed and specific throughput [1]. The quantification of dispersive mixing allows for better control of a compounding process and can be used to design new processes. During the development of a new compounding process, screw geometries and operating conditions are often refined on a laboratory-scale extruder and then scaled up to a manufacturing level. Scale-up rules are used to translate the operating conditions of a process to different sizes of extruders. In a compounding process, the goal when scaling-up is to maintain the same material properties on both scales by achieving equivalent mixing. The RSD methodology can be used to evaluate the effectiveness of scale-up rules by comparison between two or more scales. This paper will demonstrate the utility of the RSD in evaluation of two unique scale-up rules. Conventional industry practice is based on the volumetric flow comparison between extruders. The proposed approach demonstrates that in order to maintain equivalent dispersive mixing between different sizes of extruders, the degree of fill, or the percent drag flow (%DF), must be kept equivalent in the primary mixing region. The effectiveness of both rules has been evaluated by experimental application of the RSD methodology. A design of experiment approach was used to generate predictive equations for each scale-up rule that were compared to the behavior of the original small-scale extruder. Statistical comparison of the two scale-up rules showed that the %DF rule predicted operating conditions on the large-scale extruder that produced percent break-up behavior more similar to the small-scale behavior. From these results, it can be concluded that the %DF scale-up rule can be used to accurately scale operating conditions between different-sized extruders to ensure similar dispersive mixing between two processes. This will allow for greater accuracy when recreating the material properties of a small-scale twin-screw compounding process on a larger, mass production machine.

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