Flow Loop Research Articles

Toward production zonal flow allocation using novel completion tracer dosing line and diffuser: Prototype laboratory flow loop experiments and computational fluid dynamics studies

Complex completion schemes with inflow control valves (ICVs) in multi-lateral wells are now the industry standard for modern fields. Understanding the production contributions from different production zones/laterals is of great importance in optimizing the zonal flow rates to prolong the field lifetimes, reduce water cuts and the associated costs, and achieve production targets. Furthermore, the improved operational efficiency can reduce the producers’ energy usages and carbon footprints for a more sustainable operation. For the past decade, inflow tracer technology based on embedding tracers in degradable polymer matrices, which are then placed in downhole completion zones at initial installation, has been used in understanding production zonal flow contributions in field demonstrations as well as in commercial projects. However, the current technology based on degradable polymers has the following limitations: (1) there are limited lifetimes for the degradable polymer matrices that will lose their functionality past their expiration dates, and (2) the tracers are released from the polymer matrices at a constant rate; so in order to create a transient for tracer flowback measurements the wells need to be shut-in for a period of time which will interfere with normal production and possibly, with the long-term productivity of the well. Here, we introduce an alternative approach for deploying inflow tracers that has no such limitations mentioned above. Specifically, we propose the installation of passive chemical tracer dosing lines connected to diffuser chambers at the annular regions downhole during completion. Pulses of tracers can be injected into the different production zones and monitored for their flowback characteristics on-demand. The passive tracer dosing lines and diffusers only require minimum upfront investments and have no limitations of lifetime compared to the degradable polymer matrices. Furthermore, the injection of tracer pulses into the annulus near production zones creates appropriate transient responses for their flowback measurements, which do not require well shut-in and will not affect normal production.Laboratory flow loop experiments and computational fluid dynamics (CFD) studies were performed to demonstrate the proposed methodology and to understand the underlying physics. Half-scale and quarter-scale flow loops made of transparent polyvinyl chloride (PVC) pipes that resemble annular regions near the ICVs were constructed with tracer dosing lines and diffusers attached within. Colored dyes were injected into the flow loops to visualize their flush out and flowback behaviors. In CFD studies, a two-step approach was used with first solving for the turbulent fluid flow profiles, and then solving for the tracer convection diffusion behaviors in the turbulent fields. The CFD model parameters were carefully matched with flow loop experiments to predict the possible real field responses. With appropriate diffuser design, we can achieve desirable zonal flow-rate-dependent tracer flowback responses with reasonable sampling times and injected tracer quantities.

Predicting pressure loss of turbulent non-Newtonian fluids in annuli under temperature and pipe rotation effects using optimization algorithms

Accurate estimation of frictional pressure loss in an annulus is crucial for selecting appropriate pump systems, determining horsepower requirements, and controlling hole cleaning. Generally, when calculating the friction factor, the temperature of the fluid and the rotation of the inner pipe are not considered, which can lead to errors in estimating the pressure difference in the annulus. In this study, to ensure accurate pressure drop calculations, the effects of temperature and inner pipe rotation, along with other parameters, were included. An extensive experimental study was conducted at Izmir Katip Celebi University’s Flow Loop using two Carboxymethyl cellulose (CMC) solutions, across various fluid velocities, fluid temperatures, diameter ratios, and inner pipe rotation speeds. A dimensional analysis was performed to identify the parameters that affect friction factors in the annulus. Finally, friction factor equations were developed based on the experimental data using optimization algorithms such as interior point (fmincon), genetic, minimax, and simulated annealing. The findings showed that the predictions from all the algorithms tested in the study closely matched the experimental results; however, the interior point algorithm (fmincon) provided the best performance, with an average absolute percentage error of 9.4%.

Development of a doubly-fed compound control for hybrid ground source heat pump systems in hot summer and cold winter areas

In hot summer and cold winter areas, the impact of soil thermal accumulation is significant even for hybrid ground source heat pump systems (HGSHPs), especially after a long-term operation. To alleviate the energy performance degradation caused by soil temperature rise, a detailed temperature field heat transfer model of ground heat exchangers (GHXs) has been established and a doubly-fed compound control for HGSHPs is developed and integrated into a central controller module. The central controller can automatically control the loop flow distribution of units and achieve group activation of GHXs based on the load sequences forecasting feedforward and system variables feedback processes. Five control modes are included in the central controller, and the energy performances and soil temperature rise distribution of the HGSHPs with different control modes for fifteen years are compared. The results indicated that the HGSHPs performs best in terms of energy performance and soil thermal alleviation with Control Unit 13. Compared to the Normal control mode, the mean water temperature of GHXs, energy consumption of the chiller and heat pump decreased by 1.6 °C, 5.9 %, and 15.5 %, respectively, and the units COP increased by 11.3 %.

Dynamic analysis for ultra-supercritical boiler water wall considering uneven heat flux distribution and combustion instability

The dynamic characteristics of water-cooled wall are of great significance to the evaluation of the safety and flexibility for the boiler during peak shaving process. However, few dynamic studies considered the uneven heat flux distribution on the water-cooled wall, let alone the variable heat load caused by the combustion instability. In this paper, a segmented dynamic model is developed for the water-cooled wall of a 660 MW ultra supercritical boiler. The model is validated under steady and dynamic working conditions, respectively. Then, the step responses of the steam temperature in different flow loops under different load conditions are comparatively studied under the disturbances of single-parameter changes. In the cases of 10 % step decrease of either the feedwater temperature, the heat load or the feedwater mass flowrate, the outlet steam temperature is influenced greatly by the step decreased feedwater temperature under 100 % BMCR condition, while it is impacted most by the step decreased feedwater mass flow under 50 % THA condition. Under these disturbances, the outlet steam temperature of the tube with higher heat loads has larger variation and longer response time. In addition, the simulated combustion instability by the sinusoidal fluctuating heat load on the water wall is employed to explore the influences of the flame fluctuation amplitude and frequency to the water wall. The maximum steam temperature rises with the increase in amplitude but drops with the frequency of flame fluctuation. The thresholds for the flame fluctuation amplitude and frequency are obtained under different load conditions.

EXPERIMENTAL INVESTIGATION AND CFD SIMULATION OF THE ORIFICE FLOW METER TO MEASURE TWO-PHASE FLOW

In this study, an investigation is conducted to examine various methods for measuring the two-phase flow of water and air. The two-phase flow loop and its equipment, including the orifice flow meter, were designed and manufactured in accordance with relevant standards. By employing the orifice flow meter in the two-phase flow loop and determining the total mass flow rate of the two-phase flow passing through it, the pressure drop of the orifice flow meter was determined for different values of the flow rate and volume fractions of the water and air phases in the two-phase flow. The Reynolds number of the two-phase flow ranged from 700 to 11000, while the air volume fraction ranged from 10% to 45%. We observed that, for the orifice flow meter, the slope of the discharge coefficient variation in relation to the two-phase flow Reynolds number was higher at low Reynolds numbers, where a laminar flow pattern was established. As the two-phase flow Reynolds number increased, the flow pattern transitioned from laminar to plug flow, resulting in a decrease in the slope. The orifice flow meter under two-phase flow conditions was simulated using computational fluid dynamics (CFD) with different turbulence models. The results indicated that the k-epsilon RNG turbulence model yielded more accurate results compared to other turbulence models. This study provides a foundation for the measurement of two-phase flows in the oil and gas industries.

On the thixotropy of cellulose nanofibril suspensions

The thixotropic behavior of mechanically disk refined cellulose nanofibril (CNF) aqueous suspensions with 100% fines content at 1 and 3 wt% concentrations was investigated through creep, shear-recovery, multiple-step oscillation, startup, and flow loop experiments. The CNF suspensions exhibited the key thixotropic characteristics such as reduction in viscosity over time and structure recovery after cessation of flow. The results of shear recovery and multiple-step oscillation experiments suggested that regardless of the CNF concentration, lower extents of deformation impede the ability of the suspension to recover its structure at rest and higher levels of shear rates and strain amplitudes facilitate the structure recovery. Furthermore, the results of the startup experiments indicate that CNF suspensions form structures at two different levels where the flocs erode each other during flow. The different types of loops found in the flow loop experiments performed at different shear rates and time intervals were categorized and analyzed in terms of the effects of erosion of flocs and fiber rearrangement during flow.

Flow field characteristic in a novel cyclone-granular bed coupled separator

The three-dimensional flow field in a novel cyclone-granular bed coupled separator was discussed experimentally with a five-hole probe system. The airflow behaviors in the annular space, separation space, and central outlet were addressed. Several significant phenomena (the squeezing effect, the top flow loop, and the rectification effect) were observed and analyzed. By comparing the three-dimensional velocity distribution in the coupled separator with different structure parameters (the coupling space index, rc = 0.37/0.44), the combined effect between the two efficient gas purifiers was demonstrated and the importance of the tangential velocity was clarified. For this purpose, the equations for the tangential velocity at four circumferential positions were fitted using regression analysis with a wide array of experimental data and effectively characterized prior experimental outcomes.

Parametric Study on Venturi Pressure Drop for Two Phase Oil (D130)-Water Flow for Different Operating Conditions – An Experimental Investigation

The governing parameters which affect pressure drop of two-phase oil-water flow across the venturi meter are water cut and angle of inclination. The study investigates experimentally the effect of inclination and water cut on pressure drop measurements across different venturi meters with beta ratios (β) = 0.4, and 0.6 for oil–water two-phase flow experiments in a 3-inch pipe for different operating conditions. Two-phase inclinable flow loop has been employed for conducting the experiments for different fluid mixture flow rates and water cuts. The working fluids utilized are Exxsol mineral oil (D130) and potable water. The experiments were conducted for water cuts varying from 0 to 100% in steps of 20%, flow rates ranging from 2000 to 12000 barrels per day (BPD), and for horizontal and vertical flow loop inclinations (0◦ and 90◦). Liquid flow rates considered in the study match flow rates of real oil wells. The results indicate that the venturi pressure drop varies linearly with water cuts for both β ratios (0.4 and 0.6). The study indicates that the effect of inclination on venturi pressure drop is not appreciable for all water cuts and flow rates. Also, from the experimental results it can be concluded that venturi with β = 0.6 is favourable for multiphase flow metering (with flow rates ranging from 8000 to 12000 BPD). The tangible findings of the study will be helpful in combating multi-phase flow challenges in oil and petroleum industries.

Multi-objective topology optimization of macro structure and microtubule network structure for self-healing material

Abstract Self-healing materials possess the capability to promptly repair minor damages occurring during service, thereby effectively preventing safety accidents. This paper investigates a multi-objective topology optimization method for the macro structure and microtubule network of self-healing materials around pure epoxy resin materials, aiming to enhance the damage healing capability of the microtubule network while meeting the mechanical performance requirements of the macro structure. By introducing the design variables of macro structure and microtubule network, the corresponding topological description functions are established respectively. And study applies logical operations and post-processing techniques to generate an embedded microtubule network structure description. The objective functions include the flexibility of the macro structure, the along-travel head loss, and the total length of the microtubule network, with material volume serving as a constraint. In order to determine the head loss of the three-dimensional microtubule network structure, a Hardy-Cross method based on flow initialization and loop search is proposed. Multi-objective topology optimization is designed based on moving morphable components algorithm, enumeration method and Pareto principle. Develop iterative termination conditions by assessing the disparity between Pareto solution sets in each generation, thereby ensuring algorithm convergence. The numerical example of the Messerschmitt–Bölkow–Blohm (MBB) beamyields a flexibility of 0.059 without a carrier and 0.0728 with a carrier the macrostructural flexibility without a carrier is 81.0% compared to with a carrier, and the macrostructural profiles and the overall flexibility of the MBB beams with/without a carrier are close to each other. This method serves as a reference for optimizing large-scale self-healing structures.

Experimental investigation of well deliquification using the partial tubing restrictions

Liquid loading is one of the main challenges in the later life of natural gas wells. Several methods have been tested to remedy this issue and unload gas wells, with various efficiencies. Preliminary studies on the impact of partial restrictions reveals that they improve liquid lifting by generating droplets and preventing the liquid film from falling back. These restrictions are commonly in shape of orifice rings or inserts. This study evaluates liquid unloading by employing such restrictions to improve liquid lifting. The restrictions can be incorporated into the tubing joint design, making them cheaper and easier to install compared to other techniques. Comprehensive experiments are conducted to understand the effect of inserts and liquid properties on two-phase flow behavior. The tests are performed in a 0.0508-m (2-inches) inner diameter vertical flow loop, using water or oil as the liquid phase and air as the gas phase. The tests are conducted with insert opening inner diameters of 0.0381 and 0.0445 m (1.5 and 1.75 inches.)The inserts cause significant mixing and generate high amplitude waves, which facilitate droplet generation. In churn flow with inserts, a thin liquid film is observed traveling downward, while liquid droplets travel upward. The results show that the inserts have the most positive effect at lower gas rates of churn flow and at lower liquid rates. Moreover, inserts provide the largest reduction in the liquid holdup for oil-air flow, due to lower density and surface tension compared to water. The results show that the inserts may enhance the liquid lifting by lowering the liquid holdup, while also increase the pressure drop by increasing the frictional losses. This indicates the need to choose the optimum insert diameter to minimize frictional losses and enhance liquid lifting.

Feasibility Testing of the Bionet Sonar Ultrasound Transcutaneous Energy Transmission (UTET) System for Wireless Power and Communication of a LVAD.

To address the clinical need for totally implantable mechanical circulatory support devices, Bionet Sonar is developing a novel Ultrasonic Transcutaneous Energy Transmission (UTET) system that is designed to eliminate external power and/or data communication drivelines. UTET systems were designed, fabricated, and pre-clinically tested using a non-clinical HeartWare HVAD in static and dynamic mock flow loop and acute animal models over a range of pump speeds (1800, 2400, 3000 RPM) and tissue analogue thicknesses (5, 10, 15mm). The prototypes demonstrated feasibility as evidenced by meeting/exceeding function, operation, and performance metrics with no system failures, including achieving receiver (harvested) power exceeding HVAD power requirements and data communication rates of 10kB/s and pump speed control (> 95% sensitivity and specificity) for all experimental test conditions, and within healthy tissue temperature range with no acute tissue damage. During early-stage development and testing, engineering challenges for UTET size reduction and stable and safe operation were identified, with solutions and plans to address the limitations in future design iterations also presented.

Development of a large diameter invitro flow loop thrombogenicity test system.

To accommodate a wider range of medical device sizes, a larger invitro flow loop thrombogenicity test system using 9.5 -mm inner diameter (ID) tubing was developed and evaluated based on our previously established 6.4 -mm ID tubing system. Four cardiopulmonary bypass roller pumps were used concurrently to drive four flow loops during testing. To ensure that each pump produced a consistent thrombogenic response for the same material under the same test conditions, a novel dynamic roller occlusion setting method was applied. Five materials with varying thrombogenic potentials were tested: polytetrafluoroethylene (PTFE), silicone, 3D-printed nylon, latex, and nitrile rubber (BUNA). Day-old bovine blood was heparinized to a donor-specific concentration and recirculated through the flow loops containing test materials at 20 rpm for 1 h at room temperature. Material thrombogenicity was characterized by measuring the thrombus surface coverage, thrombus weight, and platelet (PLT) count reduction. The larger tubing system can differentiate thrombogenic materials (latex, BUNA) from the thromboresistant PTFE material. Additionally, silicone and the 3D-printed nylon exhibited an intermediate thrombogenic response with significantly less thrombus surface coverage and PLT count reduction than latex and BUNA but more thrombus surface coverage than PTFE (p < 0.05). The 9.5 -mm ID test system can effectively differentiate materials of varying thrombogenic potentials when appropriate pump occlusion settings and donor-specific anticoagulation are used. This system is being assessed in an interlaboratory study to develop standardized best practices for performing invitro dynamic thrombogenicity testing of medical devices and materials.

Intravascular delivery of an MK2 inhibitory peptide to prevent restenosis after angioplasty

Peripheral artery disease is commonly treated with balloon angioplasty, a procedure involving minimally invasive, transluminal insertion of a catheter to the site of stenosis, where a balloon is inflated to open the blockage, restoring blood flow. However, peripheral angioplasty has a high rate of restenosis, limiting long-term patency. Therefore, angioplasty is sometimes paired with delivery of cytotoxic drugs like paclitaxel to reduce neointimal tissue formation. We pursue intravascular drug delivery strategies that target the underlying cause of restenosis - intimal hyperplasia resulting from stress-induced vascular smooth muscle cell switching from the healthy contractile into a pathological synthetic phenotype. We have established MAPKAP kinase 2 (MK2) as a driver of this phenotype switch and seek to establish convective and contact transfer (coated balloon) methods for MK2 inhibitory peptide delivery to sites of angioplasty. Using a flow loop bioreactor, we showed MK2 inhibition in ex vivo arteries suppresses smooth muscle cell phenotype switching while preserving vessel contractility. A rat carotid artery balloon injury model demonstrated inhibition of intimal hyperplasia following MK2i coated balloon treatment in vivo. These studies establish both convective and drug coated balloon strategies as promising approaches for intravascular delivery of MK2 inhibitory formulations to improve efficacy of balloon angioplasty.

Study of the effect of glycine on the growth and mobility of CO2 hydrate slurries in the loop

The stability of CO2 hydrate slurry mobility is essential for the progression of diverse potential Carbon Capture, Utilization, and Storage (CCUS) applications, while also playing a critical role in maintaining the safety of gas–liquid two-phase flow transportation pipelines. In this study, the effect of glycine on the growth and flowing characteristics of CO2 hydrate slurry was investigated for the first time using a high-pressure recirculating flow loop. A comprehensive analysis of the hydrate growth, morphology, and rheological behavior was performed. The results show that the induction time of CO2 hydrate formation could be effectively prolonged by the presence of glycine in the loop, but it cannot inhibit its rapid formation in the rapid growth period. Meanwhile, agglomeration of the slurry and adsorption on the pipe wall during the flow process were observed with the presence of glycine. The flow pattern of pure CO2 hydrate slurry was gradually transitioned from expansion flow to pseudoplastic flow with the increase of hydrate amount, and shear thinning was observed when the slurry content was not less than 7.6%. The addition of glycine significantly increases the viscosity of the slurry, which makes the slurry behave as an expanding fluid in a wider range. The tendency of shear thickening and the range of shear thickening of the slurry were enlarged. This study raises mobility security concerns for the potential application value of glycine as an LDHI. It also serves as a valuable reference for furthering the advancement of CO2 slurry as a potential application for CCUS.

Visual study of hydrate particles agglomeration and rolling characteristic in gas-oil-water phase using a flow loop

Natural gas hydrate blockage always leads to safety problems in oil and gas transportation pipelines. It is important to look for the characteristic of hydrate blockage process. The hydrate blockage was visually investigated under gas-oil-water multi-phase flow conditions in a flow loop in this study. The change of pressure drop with water conversion rate variations were detected. The hydrate particle movements were also observed in the visual pipes at different liquid loadings and water cuts. It was found that the hydrate particles may agglomerate and deposit with an obvious rolling process in low water cut conditions. The oil phase will accelerate particles agglomeration in the contact interface of oil, gas and water, and form a large number of flocculent hydrates. A theoretical hydrate particle rolling model was conducted to analysis the experiment results, and the hydrate particle velocity increases first and then decreases with the increase of particle diameter due to the comprehensive influence of van der Waals force and drag force. The results also confirmed the maximum of the pressure drop increased when the liquid loading increased. However, the hydrate formation and blockage speed also slow down due to small component of the gas phase in high liquid loading. In addition, comparing with 20 % and 80 % water cut, 50 % water cut has the fastest hydrate formation speed in different experimental conditions. Furthermore, the maximum water conversion rate increased with have a higher water cut. More hydrate will form in the condition, which will lead to the decrease of flow velocity in the pipeline.

Unveiling intricate foam behaviors and dynamic instabilities in a two-phase natural circulation loop with seawater

The use of seawater as an alternative emergency coolant in a nuclear power plant presents great potential to enhance the nuclear safety. The present study investigates the dynamic instabilities during the startup experiments of a natural circulation loop with seawater through synchronization of two-phase flow visualization and measurements of transient fluid flow parameters. The results reveal that in seawater the pressure drop oscillations (PDO) with nature of low-frequency pulse-type loop flow occurs at the modified heat flux of 531.56–654.80 kW/m2. On the other hand, the density wave oscillations (DWO) characterized by high-frequency oscillatory flow prevails at higher modified heat flux of 654.80–1844.46 kW/m2. For the loop with seawater, the flow patterns in the riser may evolve from dispersed bubbly flow, foam flow, foam and short slug flow due to the flashing effects, and foam and long slug flow periodically. The image analysis reveals that the foam fraction may decline from 75% to 52.2%, while the flow pattern transforms from the stage II (foam and cape bubbly flow) to III (foam and long slug flow). On the other hand, the flow pattern may evolve from bubbly flow, cap bubbly flow, turbulent slug flow, and long slug flow in de-ionized water. For DWO, the oscillatory frequency is found to be inlet temperature dependent. Interestingly, both fluids demonstrate identical frequencies of 0.06 Hz, 0.14 Hz, and 0.09 Hz, respectively, corresponding to the inlet temperature range of 40–52 °C, 52–65 °C, and 65–75 °C, despite significantly different evolution of two-phase flow patterns. Indeed, the density wave travels at the same speed through the loop operating at the same power for both seawater and de-ionized water, as the buoyancy force is the primary driving force for the present study. These findings contribute significantly to the better understanding of related industrial processes using seawater as the working fluid.

Numerical simulation of arc stabilizing cycle in vacuum arc remelting of titanium alloy

Through utilizing numerical simulation methods, the flow state of the molten pool during the vacuum self-consumption melting process of titanium alloy was analyzed. The influence of the stable arc cycle on the shape of the molten pool, dendrite arm spacing, surface quality, and shrinkage cavity was examined. The results showed that without an external magnetic field, the molten pool for smelting a Φ720 mm specification titanium alloy ingot is dominated by self-inductance magnetic force, leading to a downward flow in the central part of the melt. A mere 0.5 G stray magnetic field can result in Ekman pumping, causing an upward secondary flow in the core to counteract it. At an externally added magnetic field strength of 50 G, choosing a 10 s-20 s cycle can achieve a relatively stable double loop flow pattern. The shape of its molten pool, dendrite arm spacing, and contact ratio all reach optimal performance, thus verifying the possibility and feasibility of the double loop flow, and the macroscopic segregation of the simulated ingots essentially matches the experimental results, aiming to provide references for selecting parameters in actual production.

Analysis of Energy and Pressure in the Sinus with Different Blood Pressures after Bioprosthetic Aortic Valve Replacement.

To investigate the effect of changing systolic and diastolic blood pressures (SBP and DBP, respectively) on sinus flow andvalvular and epicardial coronary flow dynamics after TAVR and SAVR. SAPIEN 3 and Magna valves were deployed in an idealized aortic root model as part of a pulse duplicating left heart flow loop simulator. Different combinations of SBP and DBP were applied to the test setup and the resulting change in total coronary flow from baseline (120/60mmHg), effective orifice area (EOA), and left ventricular (LV) workload, with each combination, was assessed. In addition, particle image velocimetry was used to assess the Laplacian of pressure ( ) in the sinus, coronary and main flow velocities, the energy dissipation rate (EDR) in the sinus and the LV workload. This study shows that under an elevated SBP, there is an increase in the total coronary flow, EOA, LV workload, peak velocities downstream of the valve, , and EDR. With an elevated DBP, there was an increase in the total coronary flow and . However, EOA and LV workload decreased with an increase in DBP, and EDR increased with a decrease in DBP. Blood pressure alters the hemodynamics in the sinus and downstream flow following aortic valve replacement, potentially influencing outcomes in some patients.

A New Development of Cross-Correlation-Based Flow Estimation Validated and Optimized by CFD Simulation

The accurate measurement of mass flow rates is important in nuclear power plants. Flow meters have been invented and widely applied in several industries; however, the operating environment in advanced nuclear power plants is especially harsh due to high temperatures, high radiation, and potentially corrosive conditions. Traditional flow meters are largely limited to deployment at the outlet of pumps, on pipes, or in limited geometries. Cross-correlation function (CCF) flow estimation, on the other hand, can estimate the flow velocity indirectly without any specific instruments for flow measurement and in any geometry of the flow region. CCF flow estimation relies on redundant instruments, typically temperature sensors, in series in the direction of flow. One challenge for CCF flow estimation is that the accuracy of the flow measurement is mainly determined by inherent, common local process variation across the sensors, which may be small compared to the uncorrelated measurement noise. To differentiate the process variations from the uncorrelated noise, this research implements periodic fluid injection at a different temperature than the bulk fluid before the temperature sensors to amplify process variation. The feasibility and accuracy of this method are investigated through flow loop experiments and Computational Fluid Dynamics (CFD) simulations. This paper focuses on a CFD simulation model to verify the previous experimental results and optimize CCF flow estimation with different configurations. The optimization study is carried out to perform a grid search on the optimal location of the sensor pair under different flow rates. The CFD results show that the optimal sensor spacing depends on the flow rate being measured and provides guidance for sensor location implementation under various anticipated flow rates.

Corrosion behavior of N80 carbon steel in CO2 environments: Investigating the role of flow velocity and silty sand through experimental and computational simulation

The effects of flow velocity and silty sand on CO2 corrosion of N80 carbon steel were studied using a small flow loop. Silty sand does not change the electrochemical characterization of corrosion but reduces the corrosion rate of steel. Under the low flow velocity, silty sand embeds in the sample surface, reducing active area for iron dissolution and delaying the formation of FeCO3 in corrosion product layer. At medium and high flow velocity, silty sand erodes the sample surface, and wall shear stress damages the integrity of the corrosion product layer, but do not lead to greater corrosion rate.