Designing Fluid Velocity Profiles for Optimal Primary Cementing

1996 ◽  
Author(s):  
M.G.P. SILVA ◽  
A.L. Martins ◽  
B.C. BARBOSA ◽  
H. Garcia
Keyword(s):  
Fluid Velocity ◽  
Velocity Profiles ◽  
Primary Cementing

scholarly journals An electromagnetic arrayed pump to create arbitrary velocity profiles in fluid

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Seyed Peyman Hashemi ◽  
Mohammad Reza Karafi ◽  
Mohammad Hossein Sadeghi ◽  
Vahid Rezaei Esfedan
Keyword(s):  
Magnetic Field ◽  
Fluid Velocity ◽  
Rectangular Channel ◽  
Velocity Profiles ◽  
List Type ◽  
Finite Element Software ◽  
Electromagnetic Pump ◽  
Naoh Solution ◽  
Arbitrary Velocity ◽  
The Magnetic Field

AbstractThe present paper is conducted to develop a new structure of an electromagnetic pump capable of controlling the magnetic field in a rectangular channel. Common electromagnetic pumps do not create uniform velocity profiles in the cross-section of the channel. In these pumps, an M-shape profile is created since the fluid velocity in the vicinity of the walls is higher than that in its center. Herein, the arbitrary velocity profiles in the electromagnetic pump are generated by introducing an arrayed structure of the coils in the electromagnetic pump and implementing 3D numerical simulation in the finite element software COMSOL. The dimensions of the rectangular channel are 5.5 × 150 mm2. Moreover, the magnetic field is provided using a core with an arrayed structure made of low-carbon iron, as well as five couples of coils. 20% NaoH solution is utilized as the fluid (conductivity: 40 S/m). The arrayed pump is fabricated and experimentally created an arbitrary velocity profile. The pressure of the pump in every single array is 12 Pa and the flow rate is equal to 3375 mm3/s. According to the results, there is a good agreement between the experimental test carried out herein and the simulated models.Article highlights This is the first time that the idea of arrayed electromagnetic pump is presented. This pump uses a special arrayed core with coils; by controlling the current of each coil and the direction of the currents, the magnetic field under the core could be adjusted. By changing the magnetic field at any position in the width of the channel, the Lorentz force alters, which leads to different velocity and pressure profiles. Using COMSOL multiphysics software, the electromagnetic pump was simulated in real size compared to the experimental model. Subsequently, the simulation model was verified and different velocity profiles were generated by activation and deactivation of different coils. The pressure and velocity curves and contours were extracted. The experimental setup was manufactured and assembled. NaOH solution was utilized as the fluid. Afterwards, different modes of coil activations were investigated and the pressure and velocity profiles of the pump were calculated.

Non-Newtonian Fluid Velocity Profiles Determined with Simple Magnetic Resonance Spin Echoes

2021 ◽  
Vol 16 (2) ◽  
Author(s):  
Jiangfeng Guo ◽  
Michael M. B. Ross ◽  
Benedict Newling ◽  
Bruce J. Balcom
Keyword(s):  
Magnetic Resonance ◽  
Newtonian Fluid ◽  
Fluid Velocity ◽  
Velocity Profiles ◽  
Resonance Spin ◽  
Spin Echoes

Assessment of the Equivalent Sandbed Roughness and the Interfacial Friction Factor in Hole Cleaning With Water in a Fully Eccentric Horizontal Annulus

SPE Journal ◽  
2018 ◽  
Vol 23 (05) ◽  
pp. 1748-1767 ◽  
Author(s):  
Majid Bizhani ◽  
Ergun Kuru
Keyword(s):  
Friction Factor ◽  
Fluid Velocity ◽  
Velocity Profiles ◽  
Primary Objective ◽  
Bedload Transport ◽  
Interfacial Friction ◽  
Erosion Process ◽  
Hole Cleaning ◽  
Bed Erosion ◽  
Friction Factors

Summary In this study, we have investigated the turbulent flow of water over the sandbed deposited in a horizontal eccentric annulus. The primary objective was to determine the effect of the presence of a sandbed on the parameters strongly involved in the bed-erosion process, such as the local fluid-velocity profiles near the interface, the equivalent sandbed roughness, and the average and the interfacial friction factors. The particle-image-velocimetry (PIV) technique was used to measure the velocity distribution at the water/sandbed interface. The bedload transport of particles caused an abrupt increase in the equivalent sandbed roughness. Analyses of the velocity profiles in the wall units confirmed that the sandbed roughness is variable and can be several times greater than the mean particle size. The interfacial ( fi) and the average friction factors ( fa) were evaluated and compared with flow under the stationary-bed and the bedload-transport conditions. The interfacial friction factor increased dramatically at the onset of the bed erosion. We have also found that depending on the bed height (or the surface area of the bed at the interface), the interfacial friction factor can be significantly different from the average friction factor. The results presented here provide much-needed experimental data for the validation of the mechanistic, semimechanistic (empirical), and numerical [computational-fluid-dynamics (CFD)] models of the bed erosion process. The major conclusion of the study is that the difference between the average and interfacial friction factors should be taken into account for more-realistic multilayer modeling of the hole cleaning.

Characterization of Transition to Turbulence for Blood in a Straight Pipe Under Steady Flow Conditions

2016 ◽  
Vol 138 (7) ◽  
Author(s):  
Dipankar Biswas ◽  
David M. Casey ◽  
Douglas C. Crowder ◽  
David A. Steinman ◽  
Yang H. Yun ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Steady Flow ◽  
Newtonian Fluid ◽  
Fluid Velocity ◽  
Shear Thinning ◽  
Velocity Profiles ◽  
Transition To Turbulence ◽  
Pipe Diameter ◽  
Flow Conditions ◽  
Straight Pipe

Blood is a complex fluid that, among other things, has been established to behave as a shear thinning, non-Newtonian fluid when exposed to low shear rates (SR). Many hemodynamic investigations use a Newtonian fluid to represent blood when the flow field of study has relatively high SR (>200 s−1). Shear thinning fluids have been shown to exhibit differences in transition to turbulence (TT) compared to that of Newtonian fluids. Incorrect prediction of the transition point in a simulation could result in erroneous hemodynamic force predictions. The goal of the present study was to compare velocity profiles near TT of whole blood and Newtonian blood analogs in a straight rigid pipe with a diameter 6.35 mm under steady flow conditions. Rheology was measured for six samples of whole porcine blood and three samples of a Newtonian fluid, and the results show blood acts as a shear thinning non-Newtonian fluid. Measurements also revealed that blood viscosity at SR = 200 s−1 is significantly larger than at SR = 1000 s−1 (13.8%, p < 0.001). Doppler ultrasound (DUS) was used to measure velocity profiles for blood and Newtonian samples at different flow rates to produce Reynolds numbers (Re) ranging from 1000 to 3300 (based on viscosity at SR = 1000 s−1). Two mathematically defined methods, based on the velocity profile shape change and turbulent kinetic energy (TKE), were used to detect TT. Results show similar parabolic velocity profiles for both blood and the Newtonian fluid for Re < 2200. However, differences were observed between blood and Newtonian fluid velocity profiles for larger Re. The Newtonian fluid had blunt-like velocity profiles starting at Re = 2403 ± 8 which indicated transition. In contrast, blood did not show this velocity profile change until Re = 2871 ± 104. The Newtonian fluid had large velocity fluctuations (root mean square (RMS) > 20%) with a maximum TKE near the pipe center at Re = 2316 ± 34 which indicated transition. In contrast, blood results showed the maximum TKE at Re = 2806 ± 109. Overall, the critical Re was delayed by ∼20% (p < 0.001) for blood compared to the Newtonian fluid. Thus, a Newtonian assumption for blood at flow conditions near transition could lead to large errors in velocity prediction for steady flow in a straight pipe. However, these results are specific to this pipe diameter and not generalizable since SR is highly dependent on pipe diameter. Further research is necessary to understand this relation in different pipe sizes, more complex geometries, and under pulsatile flow conditions.

scholarly journals Parametric Analysis of Entropy Generation in Magneto-Hemodynamic Flow in a Semi-Porous Channel with OHAM and DTM

2014 ◽  
Vol 11 (1-2) ◽  
pp. 47-60 ◽  
Author(s):  
M. M. Rashidi ◽  
A. Basiri Parsa ◽  
O. Anwar Bég ◽  
L. Shamekhi ◽  
S. M. Sadri ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Entropy Generation ◽  
Hartmann Number ◽  
Fluid Velocity ◽  
Velocity Profiles ◽  
Porous Channel ◽  
Moving Plate ◽  
Optimal Homotopy Analysis Method ◽  
Transform Method ◽  
Mass Transfer Parameter

The magneto-hemodynamic laminar viscous flow of a conducting physiological fluid in a semi-porous channel under a transverse magnetic field has been analyzed by the optimal Homotopy Analysis Method (OHAM) and Differential Transform Method (DTM) under physically realistic boundary conditions first. Then as the main purpose of this study the important designing subject, entropy generation of this system, has been analyzed. The influence of Hartmann number (Ha) and transpiration Reynolds number (mass transfer parameter, Re) on the fluid velocity profiles in the channel are studied in detail first. After finding the fluid velocity profiles, graphical results are presented to investigate effects of the Reynolds number, Hartmann number,x-velocity of the moving plate, suspension height and dimensionless horizontal coordinate on the entropy generation.

Casing Centralization in Irregular Wellbores

2017 ◽  
Author(s):  
Hans Joakim Skadsem ◽  
Arild Saasen ◽  
Stein Håvardstein
Keyword(s):  
Minimum Degree ◽  
Spline Interpolation ◽  
Drilling Fluid ◽  
Fluid Velocity ◽  
String Model ◽  
Analytical Models ◽  
Transverse Displacement ◽  
Friction Forces ◽  
Narrow Side ◽  
Primary Cementing

Wellbore irregularities can cause excessive mechanical friction forces while attempting to land casing strings, and unfavorable conditions for primary cementing of casing strings. In an eccentric annulus, the fluid velocity is largest in the wide section of the annulus. The drilling fluid on the narrow side of the annulus may be immobilized due to the lower wall shear stress in this section of the annulus. A direct consequence for the primary cementing operation is the potential for having residual drilling fluid between casing and formation, and thereby failing to achieve zonal isolation and adequate mechanical support for the casing. Casing strings are usually fitted with centralizers at predetermined intervals in order to achieve a minimum degree of centralization in the wellbore and efficient fluid displacement during primary cementing. Centralizer distribution and design are based on assumptions of regular wellbore geometries and often analytical models for estimating lateral casing string displacement in the well. The latter assumption implies that bending moments are not transmitted across centralizers, and may lead to nonconservative centralizer designs. To investigate the effect of irregularity and casing string stiffness, we consider a stiff string model that approximates the casing string as finite beam elements with bending and axial degrees of freedom at each end, thereby accounting for transmission of both axial and bending stresses between elements. In this work, we evaluate wellbore irregularity by inspecting a six-arm caliper log and estimate the cross-sectional shape of the wellbore by cubic spline interpolation between the arms of the caliper tool. Analyses of the caliper logs indicate that long, continuous strecthes conform to the nominal wellbore size, and that local hole enlargements may be significant. Irregularities are found to be largely symmetric about the wellbore axis, although some examples exhibit elliptic or oval shapes that may conform with local in-situ stress directions. We detail the stiff string model assumptions and implementation for evaluating casing centralization, and demonstrate the approach on model irregularities and on selected caliper log sections. Calculations suggest that bow spring centralizers result in better casing centralization in vertical parts of the wellbore, while large bow spring compression favour rigid centralizers in more inclined parts of the well. Axial compression close to the bottom of the wellbore section leads to a geometric softening effect of the casing, which affects transverse displacement and centralization between centralizers. Higher in the well where the casing is in tension, a geometric stiffening effect reduces transverse displacement. In proximity of washed out and irregular sections, centralization is affected both by placement of the centralizers and a reduction in the restoring capability of bow spring centralizers.

MR imaging of model fluid velocity profiles

1989 ◽  
Vol 7 (1) ◽  
pp. 69-77 ◽  
Author(s):  
K.A. Kraft ◽  
P.P. Fatouros ◽  
D.Y. Fei ◽  
S.E. Rittgers ◽  
P.R.S. Kishore
Keyword(s):  
Mr Imaging ◽  
Fluid Velocity ◽  
Velocity Profiles ◽  
Model Fluid
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