Elbow Radius Research Articles

DESIGNATION OF THE HEAD LOSS COEFFICIENT IN FITTINGS CFD

The optimization of pumping systems is important because it leads to an increment of improved energy efficiency. This study analyzes the hydraulic behavior of clean water through pressurized fittings which is analyzed numerically. The numerical experiment is carried out using Ansys Fluent software. The flow characterization through the fittings was performed using the coefficient of minor losses (KL). Two short radius elbows of 45° and 90°, and a PVC tee (simple) were used. The procedure used for the development of the numerical experimentation in this study is as follows: geometry construction, discretization, boundary conditions, configuration of the numerical simulation parameters, validation, CFD parametric study, and the analysis of results. The results of the flow simulation on the meshes showed a high sensitivity to the mesh size. To determine the optimal element size, a mesh independence study was performed, which consisted of refining the mesh to stable values. The numerical results were compared with values calculated using conventional equations for minor losses in the fittings. The KL values were characterized by two methods: in the first one the behavior of KL with respect to Reynolds number in turbulent flow was studied, in the second one the relative percentage of loss error was determined in comparison with previous investigations on this subject. The numerical results showed an acceptable relative error for the three simulated fittings.

Ratcheting assessment of pressurized elbow pipes using the visco-plastic Chen-Jiao-Kim hardening rule frameworks

In this study, the ratcheting responses of pressurized long and short radius 90° elbow pipes made of 304L austenitic stainless steel under displacement-controlled cyclic loading is evaluated mainly using the Chen-Jiao-Kim (CJK) kinematic hardening rule at room temperature. Visco-plastic flow rule and isotropic hardening are introduced into the CJK model to better reflect the time-dependent behavior and cyclic hardening characteristics of the 304L stainless steel material. The model is implemented employing the user material subroutine (UMAT) in the ABAQUS finite element software. The predictions show that the maximum ratcheting strain occurs at the flank of the long and short radius 90° elbow pipes. The influence of internal pressure, cyclic loading, and bending radius on the ratcheting responses of the elbow pipes is respectively investigated. It is found that the predictions of the CJK model are very nearly the same as the test data. In addition, the ratcheting responses of two long radius elbow pipe specimens under force-controlled cyclic bending are evaluated. Further, the C-TDF (The Committee of Three Dimensional Finite Element Stress Evaluation) combined with CJK model and Linear Matching Method (LMM) is respectively used to determine the shakedown and ratcheting boundaries of the pressurized long and short radius 90° elbow pipes under displacement-controlled and force-controlled bending. The comparison with the test data in this study shows that the shakedown and ratcheting boundaries determined by LMM, divides the shakedown and ratcheting zone well.

Numerical investigation of turbulent thermal stratification at a horizontally oriented 90° pipe-elbow with varied elbow radiuses

Thermal stratification is one of the major phenomena in thermal-mixing pipe-flow, when flow streams with a large temperature difference are mixed. A new phenomenon named as tangential oscillation of thermal stratification has been found in previous investigations, which can create a regular temperature change on the pipe wall and lead to material damage due to thermal fatigue. The flow behavior and conditions for initiation of tangential oscillation that promote temperature changes and fatigue damage are still unknown. This paper aims at analyzing the effect of elbow radius on thermal stratification initiation and flow behavior at horizontally oriented 90° pipe-elbows. The thermal stratification flow and heat transfer conditions are studied by computational fluid dynamics analyses with the Large-Eddy Simulation method. The results confirm that the tangential oscillation is initiated at the elbows, and its stability, which is quantified by the Richardson-number, decreases along the flow stream at the pipe-elbow. The phenomenon of turbulent mixing enhancement has been additionally found at the elbows by comparing the temperature fluctuations and vortex structures among the studied cases. Mixing enhancement takes the lead in the competition with tangential oscillation at the elbow with the smallest radius, and creates a higher temperature fluctuation downstream of the elbow. The temperature monitor data in the flow region is analyzed to evaluate the fatigue life of the structural material. It is shown that the pipe-elbow with the smallest radius of 0.8D has a fatigue-life time of 80 days. The tangential oscillation takes the lead with the elbow radius of 2D, and reduces the fatigue life to about 15% of that with the biggest radius of 3.2D.

The Ulnar Olecranon-Coronoid Notch Angle Affects Terminal Elbow Extension in Children and Adolescents.

Limitations to terminal elbow extension (TEE) in pediatric populations have been commonly associated with the degree of ligamentous laxity and not bony factors. Ligamentous laxity, quantified through the Beighton score, is criticized for unreliably assessing joint mobility. This study aims to show that the olecranon-coronoid notch angle (OCNA) affects TEE in healthy children and adolescents. A retrospective study of 711 pediatric patients treated for upper extremity and shoulder injuries was cross-sectionally studied at 2 tertiary centers from 2014 to 2021. Radiographs were used to measure the OCNA, humerocondylar angle, proximal anterior ulnar angle, and the presence of secondary centers of ossification. A 2-axis goniometer measured clinical TEE to a firm endpoint. The statistical analysis studied the relationships between OCNA and TEE and the effect that age and sex have on these measurements. Increased TEE was associated with increased OCNA (P<0.001) when accounting for age and sex. The average OCNA was 30.0 degrees (7.5 degrees), and the average TEE was 5.6 degrees (8.0 degrees). There was a difference in OCNA between subjects who had elbow hypoextension, normal TEE, and elbow hyperextension (P<0.001). The most common injuries were distal radius fractures (182, 26%), elbow sprains and contusions (111, 16%), distal both bone forearm fractures (95, 14%), single or both bone shaft fractures (77, 11%), and supracondylar fractures (74, 11%). These results show that the orientation of the opening of the olecranon-coronoid notch influences the arc of TEE motion in a healthy pediatric population. The notch restrains TEE by activating the bony block mechanism between the olecranon apophysis and the olecranon fossa. The measurement of the OCNA can serve as a reproducible and quantitative method to predict hypomobility to hypermobility of TEE motion. Prognostic study: Level II.

Evaluation of the Environmental Fatigue at a Long Radius Elbow of a Piping System under Transient Thermo Mechanical Stresses

Thermal fatigue widely takes place in light water reactor (LWR) piping systems. It is an important aging mechanism of a nuclear reactor. Thermal transient effects occur at the startup and shutdown of a nuclear power plant. During the thermal transients, local and global cyclic stresses are induced in the piping systems. They are exacerbated by local geometric imperfections and environmental factors, which may lead to crack initiation. The elbows of such piping systems are subject to various combinations of loads (internal pressure, bending, and torsion, as well as thermal fluctuations) during their service life. As can be seen, high-stress concentrations are developed in these piping elements. Therefore, it is important to make a failure evaluation. In this paper, a 12” pipe system segment, which was made with SA 106 Gr C steel, has been considered. It was composed by two straight sections joined by a long radius elbow. Typical start-up and shutdown transient effects of a BWR-5 were considered. A computer-aided thermo-mechanical analysis was carried out using the finite element method. The linearization of the stresses was considered, based on the ASME B &amp; PVC Code Section III, subsection NB. Under these conditions, environmental fatigue was analyzed after 40-and 60-years operation.

Impact of the COVID-19 pandemic on the trauma and orthopaedic department at level one Major Trauma Centre in the republic of Ireland

The Coronavirus Disease (COVID-19) has been identified as the cause of a rapidly spreading respiratory illness in Wuhan, Hubei Province, China in early December 2019. Since then, the free movement of people has decreased. The trauma-related injuries and the demand on the trauma and orthopaedic service would be expected to fall. The aim of this study to examine the impact of the COVID-19 pandemic on a level 1 Trauma Centre in the Republic of Ireland (ROI). Patients admitted to the Trauma & Orthopaedic (T&O) Department at Cork University Hospital (CUH) and the South Infirmary Victoria University Hospital (SIVUH), and their associated fracture patterns and management, between 01/03/20 and the 15/04/20 were documented and compared to the patient admissions from the same time period one year earlier in 2019. The total number of T&O operations performed decreased by 10.15% (P= 0.03)between the two time periods. The number of paediatric procedures fell by 40.32% (P= 0.15). Adult Distal radius and paediatric elbow fractures (excluding supracondylar fracture) increased by 88% and 13% (P= 0.19), (P= 0.04) respectively. Hip fractures remained the most common fracture-type admitted for surgery. The COVID-19 crisis has to lead to a decrease in the total numbers of trauma surgeries in a major trauma centre in the ROI. This decline is most evident in the number of paediatric and male adult patients presenting with fractures requiring operative management. Interestingly, fractures directly related to solo outdoor activities, such as running or cycling, as well as simple mechanical falls like ankle, distal radius, elbow, and hand fractures all increased. Irish males were more compliant with outdoors restrictions than females.

Numerical investigation on sealing performance of drainage pipeline inspection gauge crossing pipeline elbows

AbstractA pipeline inspection gauge (PIG) is routinely passed throughout the long‐distance oil and gas pipelines by pipeline operators to clean the pipeline. Sealing performance is a significant evaluation index for PIG's safety operation. To comprehensively evaluate the PIG's seal performance, nonlinear finite element models were developed, and parametric analysis was conducted in this study. The accuracy of simulation model was validated from numerical and experimental results reported in the literature. The results show that comparing with the pigging in straight pipes, the sealing rubber cups of PIGs can be more easily detached from the pipe wall when passing through elbows, causing smaller sealing areas. For a typical elbow (with curvature radius equals to six times of pipe diameter) widely used in pipeline industry, the minimum sealing area of rubber cup is only 8.07% during common operation conditions. The sealing ability of rubber cups can be obviously enhanced by increasing the curvature radius for the pigging operation of small curvature elbow. Elbow radius slightly affects the cup's sealing behavior when the curvature radius is over six times of pipe's outer diameter. An increment in sealing cup interference can increase the contact area between cup and pipe wall, and the blockage risk of PIGs will be reduced due to the good sealing ability and sufficient driving force. The minimum interference required for the cups is 4% under a most common operation condition; that is, the sealing cup thickness, fluid pressure difference, and friction coefficient are 35 mm, 0.02 MPa, and 0.3, respectively. A proper decrease in sealing cup thickness will reduce the stiffness of rubber cups, indicating that the cups with a smaller thickness are more prone to deformation. Thus, an increase in differential pressure over PIG can enhance the sealing performance of cups when the cups are separated from pipe wall. A large friction coefficient is risky for a safe pigging due to the decrease in sealing region with the increase in friction coefficient. In engineering practice, proper measures should be taken to reduce friction force. Above all, the results obtained in this study provide a reference for the structural design of PIGs.

Numerical investigation of gas-liquid hydrodynamics during trapped-liquid displacement from low sections of high-pressure gas pipelines

Assuring the displacement of trapped liquids from low sections by gas flow is essential for a proper operation of high-pressure natural gas pipelines. Numerical investigation of the associated transient turbulent high-pressure gas-liquid flow can provide understanding of the involved two-phase flow phenomena. To this aim, the numerical tool OpenFOAM has been used for simulating the gas-liquid flow encountered in a pipeline of a long shallow upward inclined section connected to a horizontal section by an elbow. Effects of various system parameters (e.g., gas pressure, liquid properties, up-comer inclination, elbow radius of curvature) on the gas-liquid flow dynamics are studied. Since 3D transient numerical simulations are more challenging, results obtained by 2D and 3D numerical simulations are compared to identify the similarities, sources of discrepancies, and their significance. Quantitative integral flow characteristics and the associated local flow phenomena are examined. 3D simulations verify the main findings of 2D simulations concerning the flow pattern, the associated critical gas velocity for purging the liquid and liquid propagation rate at supercritical gas velocities. The critical gas flow rate required to purge out the accumulated liquid is associated with that required to mobilize the liquid film tail along the up-comer. The main differences between 3D and 2D simulation results were captured near the elbows. The 3D effects, which result from the centrifugal force acting on the gas during its flow through the elbow, affect the downstream axial gas velocity profile and the secondary flow pattern (i.e., Dean vortices). The resulting higher interfacial shear exerted by the gas on the liquid film tail is the source of the deviations between the 3D and 2D simulation results. However, 2D simulations are sufficient for representing the gas-liquid dynamics out of the elbows’ influence region, where their effects on the flow fade out.

Numerical and experimental simulation of gas-liquid two-phase flow in 90-degree elbow

In the present research, the effects of four 90-degree horizontal elbows with different curvature radii (17, 34, 51, and 68 cm) and an identical rectangular cross-section (20 * 34 mm) on a gas–liquid slug flow pattern have been studied experimentally and numerically. Gas and liquid superficial velocities in numerical and experimental parts were set in 2.5 m/s and 0.44 m/s, respectively. In the computational fluid dynamics section, the distribution of volume fraction, velocity, pressure, turbulence intensity, and swirling intensity parameters were investigated using the VoF model and the SST k-ω method. Experimental studies were conducted utilizing pressure data and signal processing tools to study the dominant frequency of slug flow alongside bandwidth distribution as well as the Shannon entropy. The results exhibited that although the dominant frequency of slug flow did not change after passing the 90-degree elbow, the frequency signal's bandwidth increased. In this regard, the application of Shannon entropy quantity revealed that the frequency distribution signal experienced a greater increase in bandwidth as the elbows’ curvature radius increases. The turbulent intensity of the elbows’ outlet reveals that by increasing the curvature radius, the flow field behaves smoother. Also, swirling intensity distribution shows that decreasing the elbow radius leads to increment in the swirling intensity.

Numerical Simulation of Elbow Erosion in Shale Gas Fields under Gas-Solid Two-Phase Flow

Erosion is one of the most common forms of material failure and equipment damage in gas transmission pipelines. Shale gas fields use hydraulic fracturing whereby solid particles are often carried in the gas flow, and the pipeline is in a high-pressure state, which is more likely to cause erosion. The prediction of particle erosion regulation in gas-solid two-phase flow is an effective means to ensure the safe operation of shale gas fields. In this paper, an integrated CFD-DPM model is established to investigate the erosion of 90° elbow in a shale gas field under gas-solid two-phase flow, employing the realizable k-ε turbulence model, discrete phase model, and erosion rate prediction model. The reliability of the proposed numerical models is verified by comparing the predicted data with the experimental data. Moreover, the effects of six important factors on maximum erosion rate are analyzed, including gas velocity, mass flow rate of sand particles, particle diameter, shape coefficient of sand particles, pipeline diameter, elbow radius of curvature. Specifically, the results indicate that the gas velocity, mass flow rate and shape coefficient of sand particles are positively correlated with the maximum erosion rate, while the pipe diameter and the elbow radius of curvature are negatively correlated with the maximum erosion rate. A new correlation was developed, which included four dimensionless groups, namely Reynolds number, diameter ratio, density ratio and particle number. The correlation can be used to predict maximum corrosion rate of elbows. This work can provide data reference and theoretical basis for mitigating the erosion rate of pipelines and managing the integrity of gas pipelines.

Study of Erosion Behavior in Elbows Mounted in Series Using Computational Fluid Dynamics Method

Abstract To date, numerous studies using experimental methods or computational fluid dynamics (CFD) simulations to investigate erosion in elbows have been published. However, most of these studies focused on erosion caused by large particles flowing through a single elbow, whereas erosion due to small particles in elbows mounted in series is largely ignored. Studying erosion in elbows mounted in series is essential for improving the design of pipeline systems. In this paper, a CFD model is developed and validated against experimental data in the literature. The effects of both the connecting length (i.e., the distance between two elbows connected in series) and the elbow radius of curvature on erosion behavior were investigated using the verified model. In addition, the Dean number and Stokes number were used to investigate particle motion. The results show that erosion in the second elbow first decreases and then increases, as the connecting length increases, and the maximum erosion zone always occurs in the first elbow. However, when the number of elbows is increased to four, interestingly, the maximum erosion zone is located in the fourth elbow. The findings are valuable and provide guidance for designing novel pipeline systems that can mitigate erosion.

ANALISIS TEGANGAN PADA ELBOW PIPE SA 123 Gr.T22 DI SHELL AND TUBE HEAT EXCHANGER

Heat exchanger is a system used to transfer heat between fluids. The most cases of heat exchanger failure is leakage pipe. This study aims to see the effect of increasing the radius of the elbow pipe in the shell and tube heat exchanger on the stress due to internal and external pressure. The research using ANSYS 15 at elbow pipe radius 40 mm, 51 mm and 62 mm with internal pressure 20.4 MPa and external pressure 2.04 MPa. Obtained maximum results occur in 40 mm radius elbow pipe of 81,528 MPa and minimum result occurs in 62 mm of 76,212 MPa. The stress that occurs in all elbow pipe can be said safe because the stress value is still under the pipe material yield point.

Research on the influencing factors of small bending radius elbow stamping based on CAE simulation

The elbow with small bending radius is widely used in heating system and line collecting system, but its processing is difficult. Using the way of sheet metal stamping processing half elbows, and then welding the two half elbows is an effective method. There are a series of key parameters in the process of elbow stamping, which directly affect the forming result. Using sheet metal stamping software for stamping simulation, and comparing the effects of the parameters on thinning and principal stresses, we can see the specific effects of different parameters on the shaping. The main influencing factors of elbow stamping include friction coefficient, clearance, blank holding force and sheet metal thickness. For the friction coefficient and blank holder force, it should be selected near the minimum value. For clearance and sheet metal thickness, it is proportional to the forming effect.

PrEvention of posttraumatic contractuRes with Ketotifen 2 (PERK 2) \u2013 protocol for a multicenter randomized clinical trial

BackgroundInjuries and resulting stiffness around joints, especially the elbow, have huge psychological effects by reducing quality of life through interference with normal daily activities such as feeding, dressing, grooming, and reaching for objects. Over the last several years and through numerous research results, the myofibroblast-mast cell-neuropeptide axis of fibrosis had been implicated in post-traumatic joint contractures. Pre-clinical models and a pilot randomized clinical trial (RCT) demonstrated the feasibility and safety of using Ketotifen Fumarate (KF), a mast cell stabilizer to prevent elbow joint contractures. This study aims to evaluate the efficacy of KF in reducing joint contracture severity in adult participants with operately treated elbow fractures and/or dislocations.Methods/designA Phase III randomized, controlled, double-blinded multicentre trial with 3 parallel groups (KF 2 mg or 5 mg or lactose placebo twice daily orally for 6 weeks). The study population consist of adults who are at least 18 years old and within 7 days of injury. The types of injuries are distal humerus (AO/OTA type 13) and/or proximal ulna and/or proximal radius fractures (AO/OTA type 2 U1 and/or 2R1) and/or elbow dislocations (open fractures with or without nerve injury may be included). A stratified randomization scheme by hospital site will be used to assign eligible participants to the groups in a 1:1:1 ratio. The primary outcome is change in elbow flexion-extension range of motion (ROM) arc from baseline to 12 weeks post-randomization. The secondary outcomes are changes in ROM from baseline to 6, 24 & 52 weeks, PROMs at 2, 6, 12, 24 & 52 weeks and impact of KF on safety including serious adverse events and fracture healing. Descriptive analysis for all outcomes will be reported and ANCOVA be used to evaluate the efficacy KF over lactose placebo with respect to the improvement in ROM.DiscussionThe results of this study will provide evidence for the use of KF in reducing post-traumatic joint contractures and improving quality of life after joint injuries.Trial registrationThis study was prospectively registered (July 10, 2018) with ClinicalTrials.gov reference: NCT03582176.

Numerical investigation of leakage behaviour in long radius elbows

This paper focuses on the relationship between leakage opening areas and pressure heads for 90° long radius elbows under elastic limits using finite element analysis (SAP 2000). The results indicate that leakage opening areas grow linearly as the system pressure increases and the relation is described by the pressure–area slope (M). A sensitivity study was performed to show the effect of various parameters on M, as well as the leakage exponent (N). It was found that elbow internal diameter has the largest influence on the pressure–area slope, followed by the modulus of elasticity and finally elbow wall thickness. The longitudinal stress and Poisson’s ratio have a negligible effect on M. Furthermore, leak quantity is related to the pressure raised to a power ranging from 0.495 to 0.592. Regression analysis was used to derive an empirical equation to predict the pressure–area slope of round holes within elbows with different properties.&#x0D;

An Experimental Study on the Erosion-Corrosion Performance of AISI 1018 Carbon Steel and AISI 304L Stainless Steel 90-Degree Elbow Pipe

Erosion-corrosion is an unavoidable material degradation process in flow pipelines transporting abrasive particles with carrier fluids. In this study, the multiphase flow loop apparatus is employed to assess the erosion-corrosion behavior and mechanism relative to AISI 1018 carbon steel (CS) and AISI 304L stainless steel (SS) 90° long radius elbows with the inner diameter of 50.8 mm. Fine silica sand of 50 µm average size was used as a dispersed phase and erosion-corrosion tests were conducted for slug flow conditions. The erosion-corrosion analysis of 90° elbows was determined from its surface morphologies before and after the experiment using confocal and scanning electron microscopy (SEM). The direct mass loss was measured to quantify the erosion-corrosion rate of the elbow configurations. Additionally, multilayer paint modeling experiments were performed to relate qualitative inferences on erosion distribution and location with the erosion-corrosion mechanism. It was observed that the erosion or corrosion pitting mechanism prevailed on the 1018 CS elbow surface, and the 304L SS displayed excellent erosion-corrosion resistance properties. Moreover, the erosion-corrosion rate was found to be 4.12 times more in the 1018 CS compared to the 304L SS with the maximum particle impaction identified at the exit of the horizontal-horizontal (H-H) 90° elbow for slug flow.

Radiographic evaluation of the forelimbs and hind limbs of marmosets (Callithrix spp.).

The maintenance of marmosets in captivity may trigger various disorders. The objective of this study was to provide a radiographic evaluation of the forelimbs and hind limbs of marmosets rescued from illegal wildlife trade and maintained in captivity. Fourteen marmosets were studied. Three marmosets were apparently normal. Of the eleven marmosets with radiographic changes in the hind limbs, five had pelvic narrowing and bilateral varus deviation of the femur, with one suggestive of rickets and another of osteomalacia. The other marmosets showed changes such as malunion of acetabular fracture, transtibial amputation, tibial antecurvatum, and knee osteoarthritis. Six marmosets showed alterations in the forelimbs such as radius fracture, scapulohumeral subluxation, and elbow joint incongruence. In conclusion, 78.57% of the marmosets had bone and/or joint changes detected by plain radiography, which were found predominantly in the hind limbs and without impediment to locomotion in captivity.

Experimental Study of Single Stage Centrifugal Pump Characteristics and Cussons Friction Loss Apparatus

Water is a primary need for human life. Because of its important use, an integrated system was built consisting of pumps and pipes to distribute water. The phenomenon of energy loss is found in the process of distributing water using pumps and pipes. To understand the energy loss phenomenon that occurs, an experimental test is carried out on a piping installation. Fluid mechanics and turbomachinery laboratories have experimental test equipment in the form of CUSSONS friction loss in pipe apparatus with a single-stage centrifugal pump to study the energy loss phenomenon that occurs in piping installations. This test equipment is composed of two kinds of pipe materials, namely PVC and acrylic, with variations in pipe diameter of 0.75 and 1.0 inch, flow meters in the form of venturi and orifice, pipe fittings in the form of elbow 45◦ , long radius elbow 90◦ , short radius elbow 90◦ , a valve in the form of ball-valve and pump connected to the NEWMAN electric motor which has a power of 1.5 HP and a rotational speed of 2850 RPM. The pressure drop in the piping installation was measured using a mercury manometer, the increase in pump pressure was measured with a pressure gauge, and the current and voltage of the motor pump were measured using a clamp meter. The flow rate for the installation was varied between 10L/min to 55 L/min with an increase in the flow rate of 5 L/min for the data collection on straight-pipe line I, fittings, and ball valves, on straight-pipe line II the variation of discharge only reached 40 L/min, while the variation of discharge for the flow meters was from 10 L/min to 30 L/min with an increase in the flow rate of 2 L/min for the orifice and 4 L/min for the venturi. Based on the experimental test data, it was found that the loss coefficient value (Kl) for K90= 0.58, for K45= 0.38, KBV = 0.62, and KLRE= 0.611. Relative roughness (e/D) on pipe line I= 0.0043 and pipe line II = 0.024. The coefficient of discharge (Cd) on the venture-type flow meter Ce= 0.91 and Co= 0.72 at maximum discharge. Maximum pump efficiency (ηp) was 27.1% when the pump head= 18.79 m.

Development of a novel constitutive model for improved structural integrity analysis of piping components

Elbows are critical components of piping systems in the nuclear power industry, however, existing constitutive models are unable to simulate the low-cycle fatigue and ratcheting responses of this component. This study developed a constitutive model, incorporating a novel and various advanced uniaxial and multiaxial modeling features for successful response simulations of stainless steel (SS) 304 short and long radius elbows subjected to internal pressure and opening-closing displacement-controlled cycles. Simulated results demonstrate that if an existing advanced constitutive model is calibrated solely based on the material level responses, it is not able to simulate the elbow responses with acceptable accuracy. This drawback is primarily attributed to the fact that the prior loading and loading histories at different locations in an elbow are different and not represented by the loading histories of the material experiments performed for model parameter determination. Hence, model development and simultaneous experimental verification at the material and component levels trace the drawbacks of the constitutive modeling features effectively. Such evaluation of the simulated responses at two levels provided a novel modeling concept in improving the elbow response simulations quite satisfactorily. The implemented modeling features and response simulations at both levels are presented and critically analyzed for providing insights in developing robust constitutive models for structural integrity analysis.

Effect of Meter Orientation Downstream of a Short Radius Elbow on Electromagnetic Flow Meters

Electromagnetic flow meters (known as magnetic flow meters) are a widely used type of flow meter. This study examines the performance of magnetic flow meters when the electrodes in the meter are positioned at two different orientations: electrodes parallel with the plane of an upstream 90° short radius elbow and electrodes perpendicular to the plane of an upstream 90° short radius elbow. Four different meters from four different manufacturers were included in the study in which a baseline straight pipe test was first performed using more than 50 diameters of straight pipe upstream of each meter. The four meters were then installed at five different locations downstream from a 90° short-radius elbow. At each location, the meters were tested in two orientations at five different flow rates. From this study, shifts in the flow rate were observed with the electrodes located at two different orientations. These shifts in flow rate ranged from 0.01% to 4.40% of the total flow measurement, and the average shifts in flow rate ranged from 0.07% to 2.78%. For the purposes of this study, the shift in flow rate is the percentage relative to the baseline test. The results from this study illustrated that there is a significant difference in measurement accuracy when the meter electrodes are installed at different orientations relative to the plane of the bend.