CFD Simulation of Helium Flow Loop Test Section

2021 ◽  
pp. 1-11
Author(s):  
Monica Gehrig ◽  
Joshua Schlegel ◽  
Dennis Youchison ◽  
Arnold Lumsdaine ◽  
Charles Kessel ◽  
...  
Keyword(s):  
Test Section ◽  
Cfd Simulation ◽  
Flow Loop ◽  
Helium Flow

Full Scale Flow Loop Experiments of Hole Cleaning Performances of Drilling Fluids

2015 ◽  
Author(s):  
Jan David Ytrehus ◽  
Ali Taghipour ◽  
Sneha Sayindla ◽  
Bjørnar Lund ◽  
Benjamin Werner ◽  
...  
Keyword(s):  
Test Section ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Flow Loop ◽  
Base Oil ◽  
Hole Cleaning ◽  
Cleaning Performance ◽  
Water Based ◽  
Fluid Properties ◽  
Drilling Cost

One important requirement for a drilling fluid is the ability to transport the cuttings out of the borehole. Improved hole cleaning is a key to solve several challenges in the drilling industry and will allow both longer wells and improved quality of well construction. It has been observed, however, that drilling fluids with similar properties according to the API standard can have significantly different behavior with respect to hole cleaning performance. The reasons for this are not fully understood. This paper presents results from flow loop laboratory tests without and with injected cuttings size particles using a base oil and a commercial oil based drilling fluid. The results demonstrate the importance of the rheological properties of the fluids for the hole cleaning performance. A thorough investigation of the viscoelastic properties of the fluids was performed with a Fann viscometer and a Paar-Physica rheometer, and was used to interpret the results from the flow loop experiments. Improved understanding of the fluid properties relevant to hole cleaning performance will help develop better models of wellbore hydraulics used in planning of well operations. Eventually this may lead to higher ROP with water based drilling fluids as obtained with oil based drilling fluids. This may ease cuttings handling in many operations and thereby significantly reduce the drilling cost using (normally) more environmentally friendly fluids. The experiments have been conducted as part of an industry-sponsored research project where understanding the hole cleaning performance of various oil and water based drilling fluids is the aim. The experiments have been performed under realistic conditions. The flow loop includes a 10 meter long test section with 2″ OD freely rotating drillstring inside a 4″ ID wellbore made of concrete. Sand particles were injected while circulating the drilling fluid through the test section in horizontal position.

Flow Loop Investigation of Lubricant Concentration Effect on Mechanical Friction in Drilling Fluids

2016 ◽  
Author(s):  
Jan David Ytrehus ◽  
Ali Taghipour ◽  
Knud Richard Gyland ◽  
Bjørnar Lund ◽  
Sneha Sayindla ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
North Sea ◽  
Test Section ◽  
Drilling Fluid ◽  
Drill String ◽  
Drilling Fluids ◽  
Flow Loop ◽  
Steel Tubing ◽  
Steel Sections ◽  
Concrete Elements

A laboratory scale flow loop for drilling applications has been used for evaluating the effect of lubricants on skin friction during drilling and completion with oil based or low solids oil based fluids. The flow loop included a 10 meter long test section with 2″ OD free whirling rotating drill string inside a 4″ ID wellbore made of concrete elements positioned inside a steel tubing. A transparent part of the housing was located in the middle of the test section, separating two steel sections of equal length. The entire test section was mounted on a steel frame which can be tilted from horizontal to 30° inclination. The drilling fluids and additives in these experiments were similar to those used in specific fields in NCS. Friction coefficient was calculated from the measured torque for different flow velocities and rotational velocities and the force perpendicular to the surface caused by the buoyed weight of the string. The main objective of the article has been to quantify the effect on mechanical friction when applying different concentrations of an oil-based lubricant into an ordinary oil based drilling fluid and a low solids oil based drilling fluid used in a North Sea drilling and completion operation.

Assessment of Internal Tubular Coating Using Flow Loop

2021 ◽  
Author(s):  
Muzdalifah Zakaria ◽  
Shalabi A. M Sauri
Keyword(s):  
Test Section ◽  
Visual Inspection ◽  
Fluid Velocity ◽  
Surface Preparation ◽  
Deionized Water ◽  
Bend Section ◽  
Flow Loop ◽  
Coating Performance ◽  
Abrasion Test ◽  
Actual Field

Abstract Assessment of coating performance under flowing condition by using a proprietary flow loop system has been established. The 2 3/8" flow loop was designed to maintain a flow rate of 0.03-0.04 m3/sec, pressure of 3300kPa and temperature of 150°C to simulate actual field condition. Test section consisting of two 35" straight tubes with 45° elbow was internally coated and connected to the flow loop which was run continuously for 14 days with deionized water under the specified test condition. Upon completion, visual inspection, EIS and linear abrasion test were done on the test section to evaluate the coating integrity post exposure. Small blisters were noted at the elbow section potentially due to the improper surface preparation and/or higher fluid velocity at the bend section. Impedance value of 107 Ω/cm2 is a magnitude higher than the acceptance limit of 106 Ω/cm2 while abrasion resistance was found less than the set limit of <100mg/1000 cycles. The flow loop test has been shown to be a reliable tool to evaluate the effect of wall shear stress and fluid erosion on internal tubular coating.

Validation Facility and Model Development for Nuclear Fuel Assembly Response to Seismic Loading

2015 ◽  
Vol 1 (4) ◽  
Author(s):  
Noah A. Weichselbaum ◽  
Morteza Rahimi Abkenar ◽  
Marcos Vanella ◽  
Majid T. Manzari ◽  
Elias Balaras ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Test Section ◽  
Adaptive Mesh Refinement ◽  
Initial Conditions ◽  
Seismic Loading ◽  
Validation Dataset ◽  
Immersed Boundary ◽  
Flow Loop ◽  
Ground Acceleration ◽  
Fuel Assemblies

A joint experimental and numerical campaign is conducted to provide validation dataset of high-fidelity fluid–structure interaction (FSI) models of nuclear fuel assemblies during seismic loading. A refractive index-matched (RIM) flow loop is operated on a six-degree-of-freedom shake table and instrumented with nonintrusive optical diagnostics. The test section can house up to three full-height fuel assemblies. To guarantee reproducible and controlled initial conditions, special care is given to the test section inlet plenum; in particular, it is designed to minimize secondary pulsatile flow that may arise due to ground acceleration. A single transparent surrogate 6×6 fuel subassembly is used near prototypical Reynolds number, Re=105 based on hydraulic diameter. To preserve dynamic similarity of the model with prototype, the main dimensionless parameters are matched and custom spacer grids are designed. Special instruments are developed to characterize fluid and structure response and to operate in this challenging shaking environment. In parallel to the earlier experiments, we also conducted fully coupled direct numerical simulations, where the equations for the fluid and the structure are simultaneously advanced in time using a partitioned scheme. To deal with the highly complex geometrical configuration, which also involves large displacements and deformations, we utilize a second-order accurate, immersed boundary (IB) formulation, where the geometry is immersed in a block-structured grid with adaptive mesh refinement (AMR). To explore a wide parametric range, we will consider several subsets of the experimental configuration. A typical computation involves 60,000 cores, on leadership high-performance computing facilities (i.e., IBM Blue-Gene Q–MIRA).

Experimental Study of Flow Critical Heat Flux in Low Concentration Water-Based Nanofluids

2008 ◽  
Author(s):  
Sung Joong Kim ◽  
Tom McKrell ◽  
Jacopo Buongiorno ◽  
Lin-Wen Hu
Keyword(s):  
Experimental Study ◽  
Heat Flux ◽  
Critical Heat Flux ◽  
Test Section ◽  
Flow Boiling ◽  
Saturation Temperature ◽  
Outlet Temperature ◽  
Flow Loop ◽  
Maximum Heat ◽  
Low Concentration

Nanofluids are known as dispersions of nano-scale particles in solvents. Recent reviews of pool boiling experiments using nanofluids have shown that they have greatly enhanced critical heat flux (CHF). In many practical heat transfer applications, however, it is flow boiling that is of particular importance. Therefore, an experimental study was performed to verify whether or not a nanofluid can indeed enhance the CHF in the flow boiling condition. The nanofluid used in this work was a dispersion of aluminum oxide particles in water at very low concentration (≤0.1 v%). CHF was measured in a flow loop with a stainless steel grade 316 tubular test section of 5.54 mm inner diameter and 100 mm long. The test section was designed to provide a maximum heat flux of about 9.0 MW/m2, delivered by two direct current power supplies connected in parallel. More than 40 tests were conducted at three different mass fluxes of 1,500, 2,000, and 2,500 kg/m2sec while the fluid outlet temperature was limited not to exceed the saturation temperature at 0.1 MPa. The experimental results show that the CHF could be enhanced by as much as 45%. Additionally, surface inspection using Scanning Electron Microscopy reveals that the surface morphology of the test heater has been altered during the nanofluid boiling, which, in turn, provides valuable clues for explaining the CHF enhancement.

scholarly journals Computational Fontan Analysis: Preserving accuracy while expediting workflow

2021 ◽  
Author(s):  
Xiaolong Liu ◽  
Seda Aslan ◽  
Byeol Kim ◽  
Linnea Warburton ◽  
Derrick Jackson ◽  
...  
Keyword(s):  
Particle Filtering ◽  
Cfd Simulation ◽  
Fontan Operation ◽  
Flow Distribution ◽  
Mesh Size ◽  
Computational Time ◽  
Patient Specific ◽  
Flow Loop ◽  
Cfd Simulations

Background: Post-operative outcomes of the Fontan operation have been linked to graft shape after implantation. Computational fluid dynamics (CFD) simulations are used to explore different surgical options. The objective of this study is to perform a systematic in vitro validation for investigating the accuracy and efficiency of CFD simulation to predict Fontan hemodynamics. Methods: CFD simulations were performed to measure indexed power loss (iPL) and hepatic flow distribution (HFD) in 10 patient-specific Fontan models, with varying mesh and numerical solvers. The results were compared with a novel in vitro flow loop setup with 3D printed Fontan models. A high-resolution differential pressure sensor was used to measure the pressure drop for validating iPL predictions. Microparticles with particle filtering system were used to measure HFD. The computational time was measured for a representative Fontan model with different mesh sizes and numerical solvers. Results: When compared to in vitro setup, variations in CFD mesh sizes had significant effect on HFD (p = 0.0002) but no significant impact on iPL (p = 0.069). Numerical solvers had no significant impact in both iPL (p = 0.50) and HFD (P = 0.55). A transient solver with 0.5 mm mesh size requires computational time 100 times more than a steady solver with 2.5 mm mesh size to generate similar results. Conclusions: The predictive value of CFD for Fontan planning can be validated against an in vitro flow loop. The prediction accuracy can be affected by the mesh size, model shape complexity and flow competition.

Void Fraction Measurements for Air-Water Pipe Flows Using Quick-Closing Valves and Wire-Mesh Sensors

2018 ◽  
Author(s):  
Étienne Lessard ◽  
Jun Yang
Keyword(s):  
Void Fraction ◽  
Test Section ◽  
Two Phase Flow ◽  
Measurement Techniques ◽  
Wire Mesh ◽  
Axial Distance ◽  
Phase Flow ◽  
Flow Conditions ◽  
Flow Loop ◽  
Two Phase

In support of a header/feeder phenomena study, an adiabatic, near-atmospheric, air-water flow loop was commissioned simulating a single feeder of a Pressurized Heavy Water Reactor’s primary heat transport system under a postulated Loss of Coolant Accident scenario. An extensive database in representative two-phase flow conditions was collected, 750 tests in total, in order to create a two-phase flow map to be used in the more complex geometries such as header/feeder systems. The flow loop consists of two vertical test sections, for upwards and downwards flow, and one horizontal test section, each with an inner diameter of 32 mm and at least 120 diameters in length. Superficial velocities extended up to 6 m/s for the water and 10 m/s for the air. Void fraction was measured by means of quick-closing valves and a pair of wire-mesh sensors (WMS) in each test section. Two-phase repeatability tests showed that the liquid and gas superficial velocities varied by 1.1% and 0.6% at reference conditions of 2.0 and 2.8 m/s, respectively. The corresponding void fraction measurements varied for the quick-closing valves by at most 6.8%, which indicates a low sensitivity to the closure time of the valves and an appropriate axial distance between them, and 2.3% for the WMS. For both measurement techniques, the largest variations occurred in the vertical downwards test section. For the formal two-phase tests, over 600 distinct flow conditions were performed. The results showed that the two measurement techniques agreed within 5% at high void fractions and low liquid flow rates in vertical flow. For all other cases corresponding to the transitional or dispersed bubbly flow regime, the WMS over-estimated the void fraction by a consistent bias. An empirical correction is proposed, with a root-mean-square error of 6.6% across all tests. The void fraction map resulting from this database provides validation for the WMS measurements, a quantitative assessment of its uncertainty and range of applicability, and will be used as a reference in future tests under similar scale and flow conditions.

Fluid-Fluid Displacement for Primary Cementing in Deviated Washout Sections

2018 ◽  
Author(s):  
Bjørnar Lund ◽  
Jan David Ytrehus ◽  
Ali Taghipour ◽  
Shreyansh Divyankar ◽  
Arild Saasen
Keyword(s):  
Test Section ◽  
Drilling Fluid ◽  
Outer Diameter ◽  
Cement Slurry ◽  
Flow Loop ◽  
Flow Area ◽  
Fluid Displacement ◽  
Production Phase ◽  
Displacement Front ◽  
Annular Section

One of the most critical operations during well construction is the cementing procedure, where drilling fluid is displaced by cement, normally with one or more spacer fluids in between. Due to the curing nature of the cement slurry there will be only one opportunity to cement the well properly. Although one for top hole cases can fill cement in from the top in a remedial operation, this possibility cannot fully compensate for a non-optimal initial cement job. Furthermore, it cannot be applied to other well sections. In those sections, complex squeeze cementing operations may be necessary. Consequences of improper annular cement can be leakage during production phase and extensive costs when the well is to be plugged for abandonment after the production phase. To ensure that the risk of poor cement is minimised it is important to use the best procedures to place the cement properly. Most models in use assume that the annulus is homogeneous. This is not always the case since washout sections appear during drilling. The effects of these on cementing are not sufficiently studied and considered in models and procedures. Here we present and discuss results from fluid displacement experiments in a laboratory flow loop, illustrating annular displacement of drilling fluid by spacer (or spacer by cement). Model fluids with realistic densities and rheological properties have been used in a test setup with a transparent annular section. The wellbore is represented by a 10 m long test section, where the annulus has a 6,5” outer diameter and an inner string of 5” that can rotate. A washout section is represented by a 2 m long section of the outer pipe with a larger diameter of 11”. These diameters are representative for the lower parts of a well were high wellbore inclinations are common. In these sections the inner pipe cannot be assumed concentric at all times, so both concentric and eccentric positions have been tested. Experiments reported here were conducted at 60 degrees inclination. The test section was instrumented with conductivity probes in an array around the perimeter at 4 separate positions along the pipe, including the inlet and outlet of the washout section. Together with a camera along the test section, this provided information about the motion and shape of the liquid-liquid interface through the test section. Results show that the displacement front changes significantly when entering the washout zone compared to the regular annular section. Due to the larger flow area the density differences between displaced and displacing fluids become more important in the washout section, while momentum effects dominate in the regular section.

Experimental Investigation of Friction and Hydraulics in Circular and Non-Circular Wellbores With Oil Based Drilling Fluids

2017 ◽  
Author(s):  
Ali Taghipour ◽  
Bjørnar Lund ◽  
Jan David Ytrehus
Keyword(s):  
Test Section ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Drilling Process ◽  
Operational Parameters ◽  
Flow Loop ◽  
Cuttings Transport ◽  
Hole Cleaning ◽  
Experimental Laboratory ◽  
Drilling Operations

Borehole hydraulics, hole cleaning and mechanical friction are important factors for well planning and drilling operations. Many studies aim to exploit and optimize the effect of different operational parameters. The effect of wellbore geometry on hole cleaning and mechanical friction has so far not received much attention. This paper presents results from experimental laboratory tests where hydraulics, hole cleaning and mechanical friction have been investigated for circular and non-circular wellbore geometries with a relevant oil-based field drilling fluid (OBM). The non-circular wellbore geometry was made by adding spiral grooves to the wellbore walls in order to investigate the effects on cuttings transport and mechanical friction. The study contributes to describe the function and ability of deliberately induced non-circular geometry in wellbores as means to achieve a more efficient drilling and well construction. Improving hole cleaning will improve drilling efficiency in general, and will in particular enable longer reach for ERD wells. Reduced mechanical friction may improve the drilling process and many operations during the completion phase. The laboratory experiments were performed in an advanced flow loop setup reproducing field-relevant flow conditions. The flow loop consists of a 10 m long 4” inner diameter borehole made of concrete. A free whirling rotational string with 2” diameter provides a realistic down hole annular geometry. A field-relevant oil based drilling fluid (OBM) was circulated through the test section at different flow rates. To represent the effect of rate of penetration, synthetic drilling cuttings (quartz sand particles) were injected at different rates through the annulus in the horizontal test section. The test results show that borehole hydraulics and cutting transport properties are significantly improved in the non-circular wellbore relative to the circular wellbore. The effect of the mechanical friction is more complex, yet significantly different for the two geometries.

Steady Inspiratory Flow in a Model Symmetric Bifurcation

1994 ◽  
Vol 116 (4) ◽  
pp. 488-496 ◽  
Author(s):  
Yao Zhao ◽  
Baruch B. Lieber
Keyword(s):  
Test Section ◽  
Reynolds Numbers ◽  
Velocity Profiles ◽  
Axial Position ◽  
Flow Loop ◽  
Low Velocity ◽  
Cross Sectional ◽  
Branching Angle ◽  
Head Pressure ◽  
Constant Head

Flow in a bifurcating tube system typifying a major bronchial bifurcation is studied experimentally with a two color, two velocity component laser Doppler anemometer. The flow loop is composed of a pumping station, flow stratifiers and a constant head pressure tank; it can accommodate steady, pulsatile or oscillatory flow. The test section is a symmetric bifurcation of constant cross sectional area and has a branching angle of 70 deg. The test section is a cast of clear silicon rubber in a plexiglass mold that was milled on a numerically controlled milling machine. The flow division ratio from the parent to daughter branches is about unity. Steady flow results that model the inspiratory phase at Reynolds numbers of 518, 1036 and 2089, corresponding to Dean numbers of 98, 196 and 395, show that in the bifurcation plane velocity profiles in the daughter branches are skewed toward the inner wall. In the transverse plane, “m” shaped velocity profiles are found with low velocity at the center. Secondary flow patterns, which are responsible for such phenomena, are first observed at the axial position where the flow begins to turn. Flow separation was not observed at any point in the bifurcation.

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