scholarly journals Slug Translational Velocity for Highly Viscous Oil and Gas Flows in Horizontal Pipes

Fluids ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 170 ◽  
Author(s):  
Baba ◽  
Archibong-Eso ◽  
Aliyu ◽  
Ribeiro ◽  
Lao ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Prediction Models ◽  
High Viscosity ◽  
Internal Diameter ◽  
Viscosity Data ◽  
Fluid Viscosity ◽  
Liquid Viscosity ◽  
Translational Velocity ◽  
Two Phase ◽  
Low Viscosity

Slug translational velocity, described as the velocity of slug units, is the summation of the maximum mixture velocity in the slug body and the drift velocity. Existing prediction models in literature were developed based on observation from low viscosity liquids, neglecting the effects of fluid properties (i.e., viscosity). However, slug translational velocity is expected to be affected by the fluid viscosity. Here, we investigate the influence of high liquid viscosity on slug translational velocity in a horizontal pipeline of 76.2-mm internal diameter. Air and mineral oil with viscosities within the range of 1.0–5.5 Pa·s were used in this investigation. Measurement was by means of a pair of gamma densitometer with fast sampling frequencies (up to 250 Hz). The results obtained show that slug translational velocity increases with increase in liquid viscosity. Existing slug translational velocity prediction models in literature were assessed based on the present high viscosity data for which statistical analysis revealed discrepancies. In view of this, a new empirical correlation for the calculation of slug translational velocity in highly viscous two-phase flow is proposed. A comparison study and validation of the new correlation showed an improved prediction performance.

The Study of Flaws of High-Viscosity Fluids in Interaction with Peripheral Annular Water Flow in Complex Pipelines

2014 ◽  
Vol 565 ◽  
pp. 152-155
Author(s):  
A.V. Malozemov ◽  
Sergey N. Kharlamov
Keyword(s):  
Cross Sections ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Oil And Gas Industry ◽  
High Viscosity ◽  
Peripheral Region ◽  
Flow Profile ◽  
Variable Cross ◽  
Two Phase ◽  
Low Viscosity

In this paper the structure is investigated of three-dimensional flows of rheological complex media (water-oil mixtures) in pipes and channels with long and short sections of constant and variable cross-sections. This is operating units of equipment for the oil and gas industry and power engineering. The steady and unsteady modes flows are modeling of oil-water environments in the internal systems. The ability analyzed of a low-viscosity two-phase structure of the movement to regroup in the peripheral region of the pipe wall with a higher shear stress. We study the pattern of change: coefficient of friction reducing its relatively high viscosity of the nucleus by forming a water ring, local hydrodynamic parameters for complex mixtures flow. The mechanisms are obtained of the influence of flow regimes on the phase boundary. Marked parts modeling of flow profile with immiscible phases within the system full equations of two-phase flow dynamics with allowance for the effects of interfacial interaction. The particular boundary conditions discussed for these flows. The reliability calculation estimated by comparison with the existing data of similar flows (for example, A.Wegmann and P.R. Rohr’s results).

Influence of Hydrodynamic Fluid Pressure and Shoe Tread Depth on Available Coefficient of Friction

2012 ◽  
Author(s):  
Gurjeet Singh ◽  
Kurt Beschorner
Keyword(s):  
Coefficient Of Friction ◽  
Hydrodynamic Lubrication ◽  
Fluid Pressure ◽  
Hydrodynamic Pressure ◽  
High Viscosity ◽  
Health Concern ◽  
Fluid Viscosity ◽  
Low Viscosity ◽  
The Coefficient Of Friction ◽  
Lubrication Mechanisms

Slip and fall accidents are a major occupational health concern. Identifying the lubrication mechanisms affecting shoe-floor-contaminant friction under biofidelic (testing conditions that mimic human slipping) conditions is critical to identifying unsafe surfaces and designing a slip-resistant work environment. The purpose of this study is to measure the effects of varying tread design, tread depth and fluid viscosity on underfoot hydrodynamic pressure, the load supported by the fluid (i.e. load carrying capacity), and the coefficient of friction (COF) during a simulated slip. A single vinyl floor material and two shoe types (work shoe and sportswear shoe) with three different tread depths (no tread, half tread and full tread) were tested under two lubrication conditions: 1) 90% glycerol and 10% water (219 cP) and 2) 1.5% Detergent-98.5% (1.8cP) water solutions. Hydrodynamic pressures were measured with a fluid pressure sensor embedded in the floor and a forceplate was used to measure the friction and normal forces used to calculate coefficient of friction. The study showed that hydrodynamic pressure developed when high viscosity fluids were combined with no tread and resulted in a major reduction of COF (0.005). Peak hydrodynamic pressures (and load supported by the fluid) for the no tread-high viscous conditions were 234 kPa (200.5 N) and 87.63 kPa (113.3 N) for the work and sportswear shoe, respectively. Hydrodynamic pressures were negligible when at least half the tread was present or when a low viscosity fluid was used despite the fact that many of these conditions also resulted in dangerously low COF values. The study suggests that hydrodynamic lubrication is only relevant when high viscous fluids are combined with little or no tread and that other lubrication mechanisms besides hydrodynamic effects are relevant to slipping like boundary lubrication.

High-Viscosity Liquid/Gas Flow Pattern Transitions in Upward Vertical Pipe Flow

SPE Journal ◽  
2020 ◽  
Vol 25 (03) ◽  
pp. 1155-1173
Author(s):  
Eissa Al-Safran ◽  
Mohammad Ghasemi ◽  
Feras Al-Ruhaimani
Keyword(s):  
Flow Pattern ◽  
Two Phase Flow ◽  
Bubble Diameter ◽  
High Viscosity ◽  
Transition Model ◽  
Phase Flow ◽  
Liquid Viscosity ◽  
Two Phase ◽  
Flow Pattern Transition ◽  
Transition Models

Summary High-viscosity liquid two-phase upward vertical flow in wells and risers presents a new challenge for predicting pressure gradient and liquid holdup due to the poor understanding and prediction of flow pattern. The objective of this study is to investigate the effect of liquid viscosity on two-phase flow pattern in vertical pipe flow. Further objective is to develop new/improve existing mechanistic flow-pattern transition models for high-viscosity liquid two-phase-flow vertical pipes. High-viscosity liquid flow pattern two-phase flow data were collected from open literature, against which existing flow-pattern transition models were evaluated to identify discrepancies and potential improvements. The evaluation revealed that existing flow transition models do not capture the effect of liquid viscosity, resulting in poor prediction. Therefore, two bubble flow (BL)/dispersed bubble flow (DB) pattern transitions are proposed in this study for two different ranges of liquid viscosity. The first proposed transition model modifies Brodkey's critical bubble diameter (Brodkey 1967) by including liquid viscosity, which is applicable for liquid viscosity up to 100 mPa·s. The second model, which is applicable for liquid viscosities above 100 mPa·s, proposes a new critical bubble diameter on the basis of Galileo's dimensionless number. Furthermore, the existing bubbly/intermittent flow (INT) transition model on the basis of a critical gas void fraction of 0.25 (Taitel et al. 1980) is modified to account for liquid viscosity. For the INT/annular flow (AN) transition, the Wallis transition model (Wallis 1969) was evaluated and found to be able to predict the high-viscosity liquid flow pattern data more accurately than the existing models. A validation study of the proposed transition models against the entire high-viscosity liquid experimental data set revealed a significant improvement with an average error of 22.6%. Specifically, the model over-performed existing models in BL/INT and INT/AN pattern transitions.

Pressure Drop Analysis for Liquid-Liquid Downflow Through Vertical Pipe

2011 ◽  
Vol 133 (1) ◽  
Author(s):  
S. Ghosh ◽  
G. Das ◽  
P. K. Das
Keyword(s):  
Pressure Drop ◽  
Fluid Model ◽  
Flow Distribution ◽  
Separated Flow ◽  
High Viscosity ◽  
Flow Patterns ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
Low Viscosity ◽  
Two Fluid Model

In the present paper, the pressure drop characteristics and flow patterns during downward vertical flow of lube oil-water as well as kerosene-water through a circular glass conduit have been studied. Core-annular flow has been observed to be the dominant flow pattern and it gives rise to slug flow with increase of water and/or decrease of oil velocity. However, there are subtle differences in the flow distribution observed for high viscosity and low viscosity oils. The two-phase frictional pressure drop for separated flow patterns of both the liquid pairs is predicted using two-fluid model. Since the model predictions have a large mismatch with experimental data, an empirical correlation is also proposed for improved predictions. The homogeneous and drift flux models are used for slug and dispersed flow patterns.

scholarly journals Energy dissipation in microfluidic beam resonators

2010 ◽  
Vol 650 ◽  
pp. 215-250 ◽  
Author(s):  
JOHN E. SADER ◽  
THOMAS P. BURG ◽  
SCOTT R. MANALIS
Keyword(s):  
Energy Dissipation ◽  
Boundary Layers ◽  
Environmental Changes ◽  
Signal To Noise Ratio ◽  
Fluid Motion ◽  
Microfluidic Channel ◽  
Direct Consequence ◽  
High Viscosity ◽  
Fluid Viscosity ◽  
Low Viscosity

The fluid–structure interaction of resonating microcantilevers immersed in fluid has been widely studied and is a cornerstone in nanomechanical sensor development. In many applications, fluid damping imposes severe limitations by strongly degrading the signal-to-noise ratio of measurements. Recently, Burg et al. (Nature, vol. 446, 2007, pp. 1066–1069) proposed an alternative type of microcantilever device whereby a microfluidic channel was embedded inside the cantilever with vacuum outside. Remarkably, it was observed that energy dissipation in these systems was almost identical when air or liquid was passed through the channel and was 4 orders of magnitude lower than that in conventional microcantilever systems. Here, we study the fluid dynamics of these devices and present a rigorous theoretical model corroborated by experimental measurements to explain these observations. In so doing, we elucidate the dominant physical mechanisms giving rise to the unique features of these devices. Significantly, it is found that energy dissipation is not a monotonic function of fluid viscosity, but exhibits oscillatory behaviour, as fluid viscosity is increased/decreased. In the regime of low viscosity, inertia dominates the fluid motion inside the cantilever, resulting in thin viscous boundary layers – this leads to an increase in energy dissipation with increasing viscosity. In the high-viscosity regime, the boundary layers on all surfaces merge, leading to a decrease in dissipation with increasing viscosity. Effects of fluid compressibility also become significant in this latter regime and lead to rich flow behaviour. A direct consequence of these findings is that miniaturization does not necessarily result in degradation in the quality factor, which may indeed be enhanced. This highly desirable feature is unprecedented in current nanomechanical devices and permits direct miniaturization to enhance sensitivity to environmental changes, such as mass variations, in liquid.

scholarly journals Performance Prediction of a Turbodrill Based on the Properties of the Drilling Fluid

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 76
Author(s):  
Delong Zhang ◽  
Yu Wang ◽  
Junjie Sha ◽  
Yuguang He
Keyword(s):  
High Temperature ◽  
Performance Prediction ◽  
Drilling Fluid ◽  
High Viscosity ◽  
High Density ◽  
Fluid Viscosity ◽  
Two Phase ◽  
Geometry Model ◽  
Multi Stage ◽  
Fluid Properties

High-temperature geothermal well resource exploration faces high-temperature and high-pressure environments at the bottom of the hole. The all-metal turbodrill has the advantages of high-temperature resistance and corrosion resistance and has good application prospects. Multistage hydraulic components, consisting of stators and rotors, are the key to the turbodrill. The purpose of this paper is to provide a basis for designing turbodrill blades with high-density drilling fluid under high-temperature conditions. Based on the basic equation of pseudo-fluid two-phase flow and the modified Bernoulli equation, a mathematical model for the coupling of two-phase viscous fluid flow with the turbodrill blade is established. A single-stage blade performance prediction model is proposed and extended to multi-stage blades. A Computational Fluid Dynamics (CFD) model of a 100-stage turbodrill blade channel is established, and the multi-stage blade simulation results for different fluid properties are given. The analysis confirms the influence of fluid viscosity and fluid density on the output performance of the turbodrill. The research results show that compared with the condition of clear water, the high-viscosity and high-density conditions (viscosity 16 mPa∙s, density 1.4 g/cm3) will increase the braking torque of the turbodrill by 24.2%, the peak power by 19.8%, and the pressure drop by 52.1%. The results will be beneficial to the modification of the geometry model of the blade and guide the on-site application of the turbodrill to improve drilling efficiency.

scholarly journals A Two-Fluid Model for High-Viscosity Upward Annular Flow in Vertical Pipes

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3485
Author(s):  
Joseph X. F. Ribeiro ◽  
Ruiquan Liao ◽  
Aliyu M. Aliyu ◽  
Salem K. B. Ahmed ◽  
Yahaya D. Baba ◽  
...  
Keyword(s):  
Pressure Gradient ◽  
Friction Factor ◽  
Fluid Model ◽  
Flow Characteristics ◽  
Interfacial Friction ◽  
Internal Diameter ◽  
Liquid Viscosity ◽  
Two Phase ◽  
Two Fluid Model ◽  
Two Fluid

Proper selection and application of interfacial friction factor correlations has a significant impact on prediction of key flow characteristics in gas–liquid two-phase flows. In this study, experimental investigation of gas–liquid flow in a vertical pipeline with internal diameter of 0.060 m is presented. Air and oil (with viscosities ranging from 100–200 mPa s) were used as gas and liquid phases, respectively. Superficial velocities of air ranging from 22.37 to 59.06 m/s and oil ranging from 0.05 to 0.16 m/s were used as a test matrix during the experimental campaign. The influence of estimates obtained from nine interfacial friction factor models on the accuracy of predicting pressure gradient, film thickness and gas void fraction was investigated by utilising a two-fluid model. Results obtained indicate that at liquid viscosity of 100 mPa s, the interfacial friction factor correlation proposed by Belt et al. (2009) performed best for pressure gradient prediction while the Moeck (1970) correlation provided the best prediction of pressure gradient at the liquid viscosity of 200 mPa s. In general, these results indicate that the two-fluid model can accurately predict the flow characteristics for liquid viscosities used in this study when appropriate interfacial friction factor correlations are implemented.

scholarly journals Viscophobic turning regulates microalgae transport in viscosity gradients

2020 ◽  
Author(s):  
Michael R. Stehnach ◽  
Nicolas Waisbord ◽  
Derek M. Walkama ◽  
Jeffrey S. Guasto
Keyword(s):  
Cell Motility ◽  
High Viscosity ◽  
Force Model ◽  
Fluid Viscosity ◽  
Protective Effects ◽  
Microbial Transport ◽  
Cell Transport ◽  
Physical Mechanisms ◽  
Low Viscosity ◽  
Population Scale

Gradients in fluid viscosity characterize microbiomes ranging from mucus layers on marine organisms1 and human viscera2,3 to biofilms4. While such environments are widely recognized for their protective effects against pathogens and their ability to influence cell motility2,5, the physical mechanisms controlling cell transport in viscosity gradients remain elusive6–8, primarily due to a lack of quantitative observations. Through microfluidic experiments with a model biflagellated microalga (Chlamydomonas reinhardtii), we show that cells accumulate in high viscosity regions of weak gradients as expected, stemming from their locally reduced swimming speed. However, this expectation is subverted in strong viscosity gradients, where a novel viscophobic turning motility – consistent with a flagellar thrust imbalance9,10 – reorients the swimmers down the gradient and causes striking accumulation in low viscosity zones. Corroborated by Langevin simulations and a three-point force model of cell propulsion, our results illustrate how the competition between viscophobic turning and viscous slowdown ultimately dictates the fate of population scale microbial transport in viscosity gradients.

scholarly journals Auditory and Visual Crossmodal Correspondences With Haptically Perceived Liquid Viscosity

2016 ◽  
Vol 29 (8) ◽  
pp. 727-747 ◽  
Author(s):  
Jennah Asad ◽  
Mary Jane Spiller ◽  
Clare Jonas
Keyword(s):  
Letter String ◽  
Past Research ◽  
High Viscosity ◽  
Liquid Viscosity ◽  
Crossmodal Correspondences ◽  
Low Viscosity ◽  
Tactile Stimuli ◽  
Low Luminance ◽  
Size Number ◽  
Type Letter

Past research on crossmodal correspondences as they relate to tactile perception has largely been restricted to solid substances. We investigated the role of haptically explored liquid viscosity in crossmodal correspondences with visually presented luminance, saturation, roundedness, size, number and visual elevation, as well as pure-tone pitch and kiki–bouba-type letter strings. In Experiment 1, we presented two tactile and two visual or auditory stimuli simultaneously, and found significant inter-participant agreement () when pairing viscosity with luminance, saturation, roundedness, size, pitch and letter string type. To assess whether these crossmodal correspondences were relative or absolute, another 32 participants were presented, in Experiment 2, with two tactile stimuli but only one visual/auditory stimulus per trial. In this second experiment, we found that high viscosity was paired with low luminance, roundness, low saturation, and the bouba-type letter string, while low viscosity was paired with high pitch. However, the inverse associations (e.g. low viscosity with high luminance, high viscosity with low pitch) were not significant. These findings indicate that viscosity can be added to the list of dimensions that invoke crossmodal correspondences, and that the majority of crossmodal correspondences involving viscosity are absolute rather than relative, since they appear without explicit comparisons along the visual/auditory dimensions we measured.

Droplet Behavior on a Rotating Surface for Atomization-Based Cutting Fluid Application in Micromachining

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
Isha Ghai ◽  
John Wentz ◽  
Richard E. DeVor ◽  
Shiv G. Kapoor ◽  
Johnson Samuel
Keyword(s):  
Surface Tension ◽  
Evaporation Rate ◽  
High Viscosity ◽  
Cutting Fluid ◽  
Fluid Viscosity ◽  
Droplet Shape ◽  
Low Viscosity ◽  
Droplet Behavior ◽  
Rotating Surface ◽  
Cutting Zone

The droplet behavior on a rotating surface has been studied to better understand the physics underlying atomized cutting fluid application. To this end, microturning experiments are carried out and the cutting performance evaluated for varying cutting fluids and at different droplet speeds. Microturning experiments indicate that a cutting fluid with low surface tension and low viscosity generates lower cutting temperatures, whereas a fluid with low surface tension and high viscosity generates lower cutting forces. Single-droplet impingement experiments are also conducted on a rotating surface using fluids with different surface tension and viscosity values. Upon impact, the droplet shape is observed to be a function of both the droplet speed and the surface speed. The spreading increases with increased surface speed owing to the tangential momentum added by the rotating surface. Spreading is observed to also increase with a decrease in fluid surface tension and does not change with the fluid viscosity. The evaporation rate is observed to increase for a rotating surface owing to convective heat transfer. Low surface tension and low viscosity are observed to increase the evaporation rate. It is concluded that a fluid with low surface tension and low viscosity is an effective coolant of the cutting zone, whereas a fluid with low surface tension and high viscosity is effective for lubrication.

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