A New Methodology for Erosion Prediction Using Eulerian-Eulerian CFD Models

2015 ◽  
Author(s):  
Gianandrea V. Messa ◽  
Irene Ingrosso ◽  
Stefano Malavasi
Keyword(s):  
Fluid Dynamic ◽  
Fluid Phase ◽  
Impact Angle ◽  
Solid Particles ◽  
Dynamic Parameters ◽  
Gas Industry ◽  
Erosion Prediction ◽  
Cfd Models ◽  
Erosion Models ◽  
The Impact

The erosion of a surface caused by the impact of solid particles dragged by a fluid is a serious concern in the oil&gas industry. At present, the erosion prediction is performed using algebraic erosion models which express the volume of eroded material per impact as a function of the mass of the abrasive particles as well as of fluid dynamic parameters (such as the impact velocity and the impact angle of the eroding particle) and properties of the materials involved in the process. The fluid dynamic parameters are, in turn, evaluated using Eulerian-Lagrangian CFD models which interpret the fluid phase as a continuous mean and follow the trajectories of all the particles. However, the huge computational burden makes it difficult, or even precludes, to adopt this approach in many flows of engineering interest. An innovative methodology is proposed for estimating the parameters required as input by the erosion models using computationally cheaper Eulerian-Eulerian CFD models which solve for the average properties of the ensamble of particles. The good results obtained when predicting the erosion caused the by impingement of an abrasive jet against a surface make the application of this methodology to more complex flows very promising.

Kinetic Simulations for Analysing the Wall Collision Process of Non-Spherical Particles

2002 ◽  
Author(s):  
M. Sommerfeld
Keyword(s):  
Particle Shape ◽  
Fluid Dynamic ◽  
Impact Angle ◽  
Distribution Functions ◽  
Spherical Particles ◽  
Collision Process ◽  
Wall Collision ◽  
Particle Velocities ◽  
The Impact ◽  
Particle Shapes

In wall-bounded gas-solid flows the wall collision process plays an important role and may be strongly affected by wall roughness and particle shape. The modelling of the particle-wall collision mostly relies on the assumption of spherical particles. To extend such models appropriately for non-spherical particles, two-dimensional kinetic simulations were performed for different particle shapes. This implies, that the particle translational and angular motion is calculated by considering the particle shape, however neglecting fluid dynamic effects. The change of the particle velocities during the impact and rebound process was calculated by solving the impulse equations together with Coulombs law of friction. The simulations were performed for a given initial particle velocity by varying impact angle and initial angular velocity. The results for 2000 particle wall collisions allowed us to derive the distribution functions of the impact parameters required to describe the wall collision process for non-spherical particles correctly. Moreover, other wall collision properties, such as rebound angle and velocity ratios could be determined. Finally also a comparison with measurements was possible.

Surface Ripple Formation Due to Solid-Liquid Slurry Erosion

2009 ◽  
Author(s):  
Juan Liu
Keyword(s):  
Structural Steel ◽  
Laboratory Tests ◽  
Impact Angle ◽  
Solid Particles ◽  
Ceramic Surface ◽  
Metallic Surfaces ◽  
Slurry Erosion ◽  
Water Slurry ◽  
Ripple Formation ◽  
The Impact

The development of ripples and erosion on the material surfaces in a centrifugal slurry pump was investigated in laboratory tests using a sand-water slurry pot tester. The erosion of the primary material (KmTBCr26) used in the centrifugal slurry pumps was very serious. The ripple formation was influenced by the flow conditions, the impact angle of the solid particles and the particle size. Ripple formation was also observed in laboratory tests with structural steel (#40) and brittle ceramics (Al2O3, ZTA, Si3N4). The ripple profile on the structural steel surface was similar to that on the high chrome cast iron (Cr26) used in the slurry pumps. With 90° impact angles, ripples also formed on the eroded surfaces of materials tested in the sand-water slurry pot. The ripple wavelength on the ceramic surface, which was influenced by the mechanical properties and material grain size, was less than that on the metallic surfaces.

Effect of Particle Size on Magnitude and Location of Maximum Erosion in S-Bend

2014 ◽  
Author(s):  
Quamrul H. Mazumder
Keyword(s):  
Particle Size ◽  
Oil And Gas ◽  
Cfd Simulation ◽  
Flow Direction ◽  
Fluid Dynamic ◽  
Erosive Wear ◽  
Impact Angle ◽  
Solid Particles ◽  
Particle Sizes ◽  
Fluid Properties

Solid particle erosion is a micromechanical process that is influenced by flow geometry, material of the impacting surface, impact angle, particle size and shape, particle velocity, flow condition and fluid properties. Among the various factors, particle size and velocity have been considered to be the most important parameters that cause erosion. Particle size and velocity are influenced by surrounding flow velocities and carrying fluid properties. Higher erosion rates have been observed in gas-solid flow in geometries where the flow direction changes rapidly, such as elbows, tees, valves, etc., due to local turbulence and unsteady flow behaviors. S-bend geometry is widely used in different fluid handling applications such as automotive, oil and gas, arteries and blood vessels. This paper presents the results of a Computational Fluid Dynamic (CFD) simulation of diluted gas-solid and liquid-solid flows through an S-Bend and the dynamic behavior of entrained solid particles in the flow. CFD analyses were performed at five different particle sizes ranging between 50 and 300 microns. Maximum erosive wear was observed at smaller particle sizes and compared to the larger sizes. The location of maximum erosion was at different locations in the first bend as compared to the second bend.

Analysis of Erosion and Failure in the Sudden Expansion Fracturing Tubing of Deep Gas Wells

2010 ◽  
Author(s):  
Yan Xu ◽  
Zunce Wang ◽  
Sen Li ◽  
Fengxia Lv ◽  
Yuejuan Yan ◽  
...  
Keyword(s):  
Impact Angle ◽  
High Rate ◽  
Sudden Expansion ◽  
Gas Wells ◽  
Gas Well ◽  
Erosion Models ◽  
Fluid Theory ◽  
Simulation Results ◽  
The Impact ◽  
Two Fluid

With the increasing of flow rate during fracturing in deep gas well, the erosion of fracturing tubing is an issue of immense concern to the industry. Based on the Euler-Euler two–fluid theory, the numerical simulations have been performed to predict the flow field in the sudden expansion fracturing tubing. The velocity distributions and sand concentration profiles are obtained, and the simulation results show that separation and reflux come into being in the sudden expansion fracturing tubing when pumping sand slurries at high rate, and the sand concentration increases at some regions. The erosion and failure of the fracturing tubing are relevant to the sand concentration, the velocity and the impact angle. The erosion model was established with the erosion experiment, and the numerical simulation results were used to describe the erosion rate of sudden expansion fracturing tubing according to the established erosion models. The mainly erosion region obtained through the simulation is basically agree with the failure region of tubing during fracturing in deep gas wells.

Effects of Applying a Stochastic Rebound Model in Erosion Prediction of Elbow and Plugged Tee

2002 ◽  
Author(s):  
Xianghui Chen ◽  
Brenton S. McLaury ◽  
Siamack A. Shirazi
Keyword(s):  
Prediction Model ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Outer Wall ◽  
Stochastic Approach ◽  
Solid Particles ◽  
Gas Industry ◽  
Erosion Prediction ◽  
Before And After ◽  
Experimental Findings

Solid particle erosion is a complex phenomenon that depends on many factors such as particle and fluid characteristics, type of material being eroded, and flow geometry. Fittings used in the oil and gas industry such as elbows are susceptible to erosion when solid particles are present in the flow. The momentum of particles carries them across streamlines and the particles impinge the outer wall of the elbow resulting in erosion damage. In an erosive environment, plugged tees are commonly used instead of elbows to reduce the erosion especially where space considerations are important and long-radius elbows can not be used. However, it is unclear how much of a reduction in erosion occurs by replacing an elbow with a plugged tee. In order to compare the erosion in an elbow and a plugged tee exposed to the same flow conditions, a CFD-based erosion prediction model is applied. The model has three primary steps: flow modeling, particle tracking, and applying erosion equations. The results from the model agree with experimental findings for the elbow geometry. However, the simulation results for erosion rate generated for the plugged tee requires a stochastic approach. Results obtained with the erosion prediction model before and after this modification are shown.

The Effects of Constant Kinetic Energy of Different Impacting Particles on Slurry Erosion Wear of AA 6063

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Bhushan D. Nandre ◽  
Girish R. Desale
Keyword(s):  
Silicon Carbide ◽  
Kinetic Energy ◽  
Mass Loss ◽  
Material Removal ◽  
Impact Angle ◽  
Solid Particles ◽  
Erosion Wear ◽  
Normal Impact ◽  
Sem Images ◽  
The Impact

The present experimental study investigates the effect of constant kinetic energy on erosion wear of aluminum alloy 6063. Three different natural erodents (quartz, silicon carbide, and alumina) with different particle sizes are used to impact at 45 deg and 90 deg impact angles. For calculating the number of particles in the slurry pot, it is assumed that the solid particles are of spherical shape. The total numbers of impacting solid particles were kept constant by adjusting the solid concentration, velocity, and test duration. The scanning electron microscope (SEM) images of the three erodents show that the alumina particles have sharp edges with more angularity, and silicon carbide particles have subangular nature while quartz particles are blocky in shape. The mass loss per particle at 45 deg impact angle is observed higher than at normal impact angle. It may be due to the change in material removal mechanism with changing the impact angle. It is also found that the mass loss per particle from the target material having different particle size with constant kinetic energy remains constant for respective erodents. This indicates that the velocity exponent of impacting particles is around 2. The SEM images of eroded surfaces reveal the different mechanisms of material removal at 45 deg impact angle and at normal impact angle.

Uncertainty Estimation in CFD Simulations of Erosion for Elbows

2021 ◽  
Author(s):  
Elham Fallah Shojaie ◽  
Thiana A. Sedrez ◽  
Farzin Darihaki ◽  
Siamack A. Shirazi
Keyword(s):  
Solid Particle ◽  
Turbulence Models ◽  
Uncertainty Estimation ◽  
Solid Particles ◽  
Solid Particle Erosion ◽  
Particle Erosion ◽  
Cfd Simulations ◽  
Erosion Prediction ◽  
Erosion Models ◽  
Near Wall

Abstract Computational Fluid Dynamics (CFD) is used extensively in the industry and academia for analyzing the motion of solid particles and the associated solid particle erosion that may occur in various pipe components. However, CFD simulations always carry levels of inherent uncertainties due to the numerical approximations of governing equations, generated grid, and turbulence models. Also, because of the complex nature of solid particle erosion, additional uncertainties are added to erosion prediction simulations. Aspects such as particle size, number of impacts, particles’ initial condition, near-wall mesh effects, forces considered in particle tracking procedures, particle-particle interaction, and near-wall particle-fluid interactions are all possible sources of uncertainties associated with erosion prediction in CFD. Furthermore, unique problems that accompany discrete phase handling and erosion calculation needed for the industrial applications magnify the importance of uncertainty estimation in erosion calculations. Commercially available CFD codes are used with user-developed subroutines to investigate particle erosion prediction uncertainties, numerically in elbows, by considering gas and liquid flow for several pipe sizes. Moreover, different particle sizes, inlet flow velocities, turbulence models, wall functions, and erosion models are examined. According to the ASME’s Verification and Validation (V&V) standard, uncertainties are divided into 3 categories; input, numeric, and modeling. Thus, it is possible to utilize the ASME’s standard as guidance to predict uncertainty for erosion simulations. Furthermore, an extra parameter was considered for uncertainties to account for the uncertainties induced by different simulation procedures and erosion models. The current investigations resulted in developing a framework for estimating uncertainties of erosion simulation. For each simulation result, two bounds (upper and lower) were predicted for erosion. The results show that the Reynolds Stress turbulence model (RSM) and Arabnejad’s erosion model usually predict results corresponding to the lowest uncertainties.

Erosion in Swirl-Inducing Pipes

2002 ◽  
Author(s):  
R. J. K. Wood ◽  
T. F. Jones ◽  
J. Ganeshalingam
Keyword(s):  
Sliding Wear ◽  
Computational Models ◽  
Particle Distribution ◽  
Impact Angle ◽  
Pumping Power ◽  
Particulate Flows ◽  
Flow Loop ◽  
Erosion Models ◽  
The Mean ◽  
The Impact

Swirl inducing pipes are proposed for the alleviation of problems of poor particle distribution and sliding wear, particularly at downstream bends and elbows. In a well-designed conventional pipeline, the mean axial velocity to assure good dispersion of particles is much greater than the velocity required to merely transport the slurry. This gives the impetus to design swirl-inducing pipes which allow for reduced pumping power, and reduced erosion, while efficiently maintaining suspension at strategic points. This paper covers research that has been aimed at producing good distribution of particles at relatively low velocities, by applying swirl induction. Computational models for the impact velocity and impact angle in a bend have been successfully applied to the flow field and validated by experiments in a perspex flow loop including electrical resistance tomography (ERT) to confirm the placement of particle burdens. Particle impact parameters from this work have been used as inputs to erosion models to predict wall wastage rates in bends and the location of damage from well distributed and swirling particulate flows.

The Effects of Surface Treatments on Solid Particle Erosion of 12Cr Steels for USC Power Plants

2006 ◽  
Vol 118 ◽  
pp. 201-208
Author(s):  
Kee Won Urm ◽  
Sun Ho Lee ◽  
J.W. Lee ◽  
E.Y. Lee
Keyword(s):  
Solid Particle ◽  
Impact Angle ◽  
Surface Treatments ◽  
Solid Particles ◽  
Solid Particle Erosion ◽  
Particle Erosion ◽  
Hvof Spray ◽  
Bare Steel ◽  
The Impact ◽  
Turbine Bucket

12Cr steels have been applied on the turbine bucket and nozzle partition materials for the ultra super critical (USC) coal-fired power plant. Turbine bucket and nozzle materials are damaged by the solid particles within USC steam conditions. Therefore, they have been protected by the surface treatments such as ion nitriding, boriding and chrome carbide high velocity oxygen fuel (HVOF) spray coating. In this study, the surface treatment effects on the solid particle erosion (SPE) characteristic of 12Cr steels were examined in the temperature range of 540 to 620°C and the mechanisms of surface damage are investigated. The SPE of 12Cr steel originated from micro cutting, whereas, that of boriding and chrome carbide HVOF spray originated from the repeated collision, crack initiation and propagation. In case of 12Cr bare steel, the erosion of soft materials occurred in the impact angle range of 30° to 60° at test temperatures. The SPE resistances of boride and HVOF treated steels in the impact angle range of 30° to 60° at 593°C and 621°C were much higher than those of 12Cr bare steel.

scholarly journals Solid Particle Erosion Models and their Application to Predict Wear in Pelton Turbine Injector

2020 ◽  
Vol 15 (3) ◽  
pp. 349-359
Author(s):  
Tri Ratna Bajracharya ◽  
Rajendra Shrestha ◽  
Ashesh Babu Timilsina
Keyword(s):  
Impact Angle ◽  
Solid Particles ◽  
Cfd Modeling ◽  
Computational Techniques ◽  
Complex Flow ◽  
Repeated Impact ◽  
Major Barrier ◽  
Mechanical Parts ◽  
Pelton Turbine ◽  
Erosion Models

Analysis of water quality of Himalayan originated rivers reveals the heavy sediment loading with a major portion of the sediment being hard mineral, quartz. Despite the incorporation of desanders to reduce the sediment content passing through hydro mechanical parts, significant wear is being reported in south-Asian hydroelectric projects. Repeated impact of such solid particles which are harder than the material of mechanical parts (mostly steel) is known to cause the erosion. Flow parameters, impact angle, mechanical properties of wall and particle, particle shape and size are commonly explored variables that affect the erosion of solid by the sediment-laden flow. In order to predict such erosion, starting with Finnie erosion model, several other erosion models considering aforementioned variables are proposed but are mostly case dependent. Application of numerical methods to understand flow problems constitutes the field of Computational Fluid Dynamics (CFD). Due to enclosed flow, reactions turbines took accelerated development in the investigations by CFD modeling. However, free surface jet and complex flow mechanism in buckets have been a major barrier to the application of CFD in case of Pelton turbines. Recent advancements in computational techniques, technological advancements have enabled to investigate flow in Pelton turbine by CFD. However, it is least understood which among the proposed erosion models will predict erosion occurring in Pelton turbine and assembly. This article explores about erosion in Pelton turbine, various erosion models and state of the art in modeling erosion of Pelton turbine injector. It is discussed which among the erosion models shall best predict the erosion occurring in the Pelton turbine injector. A short list of erosion models is then given which can be applied for the case of erosion in Pelton turbine injectors.

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