Formulation and Experimental Validation of a New Erosion Flow Model

2016 ◽  
Author(s):  
Rebecca Owston ◽  
Dalton McKeon
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Empirical Data ◽  
Erosion Rate ◽  
Numerical Models ◽  
Experimental Testing ◽  
Fluid Viscosity ◽  
New Model ◽  
Functional Relationships ◽  
Material Hardness

In the present work, a multivariable study has been conducted to systematically evaluate the effects of impact angle, material hardness, flow rate, sand concentration, particle size, and fluid viscosity on erosion. Experimental testing consisted of a submerged sand slurry jet impacting a flat plate in different orientations. Weight loss data, as well as profilometer surface scans have been collected on coupons to fully define the erosion. Empirical data trends were evaluated to provide insights into functional relationships between erosion rate and the parameters varied in the study. Interestingly, it was determined that scaling of experimental testing with regard to proppant concentration could be accomplished, since erosion rate normalized by the mass of sand impacting the eroded surface proved to be a constant. A total of five existing computational erosion models were evaluated against experimental data for both qualitative and quantitative performance. Results indicate that two models achieve relatively good comparison with experimental data without the need for case-specific tuning of model constants. This suggests that the use of these numerical models for erosion prediction in scenarios where tuning is not possible (due to lack of time/data), may still provide a reasonable estimate for the rate of material loss on equipment. As the culmination of experimental testing and computational benchmarking efforts, a new erosion model was also formulated. This model was based on both the experimental results and behavioral observations from existing submodels. The new model explicitly included contributions to erosion from the following variables: impact velocity, particle size, material hardness, and angle of impact. Improvement in simulated erosion rate agreement with empirical data was observed for all cases over existing submodels. However, those cases with higher particle diameters benefited the most. Using the new model, error compared to experiments was below 50% for all cases except one.

A Procedure to Predict Solid Particle Erosion in Elbows and Tees

1995 ◽  
Vol 117 (1) ◽  
pp. 45-52 ◽  
Author(s):  
S. A. Shirazi ◽  
J. R. Shadley ◽  
B. S. McLaury ◽  
E. F. Rybicki
Keyword(s):  
Experimental Data ◽  
Impact Velocity ◽  
Erosion Rate ◽  
Operating Conditions ◽  
Fluid Viscosity ◽  
Erosion Rates ◽  
Sand Particles ◽  
Liquid Flows ◽  
The Impact ◽  
Sand Size

A semi-empirical procedure has been developed for predicting erosion rates in pipe geometries, such as elbows and tees. The procedure can be used to estimate safe operating conditions and velocities in oil and gas production where sand is present. In the proposed procedure, a concept is introduced that allows determination of erosion rate for different pipe geometries. In the procedure, based on empirical observations, the erosion rate is related to the impact velocity of sand particles on a pipe fitting wall. A simplified particle tracking model is developed and is used to estimate the impact velocity of sand particles moving in a stagnation region near the pipe wall. A new concept of equivalent stagnation length allows the simplified procedure to be applicable to actual pipe geometries. The “equivalent stagnation regions” of an elbow and a tee geometry of different sizes are obtained from experimental data for small pipe diameters, and a computational model is used to extend the procedure to larger pipe diameters. Currently, the prediction method applies to mild steel and accounts for the effects of sand size, shape, and density; fluid density, viscosity, and flow speed; and pipe size and shape. The proposed method has been verified for gas and liquid flows through several comparisons with experimental data reported in the literature. The results of the model accurately predict the effects of sand size and fluid viscosity observed in the experiments. Furthermore, predicted erosion rates showed good agreement with experimental data for gas, liquid, and gas-liquid flows in several 50.8-mm (2-in.) elbows and tees.

A new energy-based model to predict spray droplet diameter in comparison with momentum-based models

2018 ◽  
Vol 91 (1) ◽  
pp. 182-189
Author(s):  
Hadiseh Karimaei ◽  
Seyed Mostafa Hosseinalipour ◽  
Ramin Ghorbani
Keyword(s):  
Experimental Data ◽  
Numerical Models ◽  
Droplet Diameter ◽  
Liquid Sheet ◽  
Linear Instability ◽  
Content Type ◽  
New Model ◽  
Data Prediction ◽  
New Energy ◽  
Atomization Efficiency

Purpose To estimate mean droplet diameter (MDD) of a spray, three different numerical models were used in this paper. One of them is investigation of the surface instability of the liquid sheet producing from an injector. Design/methodology/approach First, the linear instability (LI) analysis introduced by Ibrahim (2006) is implemented. Second, the improved (ILI) analysis already introduced by the present authors is used. ILI analysis is different from the prior analysis, so that the instability of hollow-cone liquid sheet with different cone angles is investigated rather than a cylindrical liquid sheet. It means that besides the tangential and axial movements, radial movements of the liquid sheet and gas streams have been considered in the governing equations. Beside LI theory as a momentum-based approach, a new model as a theoretical energy-based (TEB) model based on the energy conservation law is proposed in this paper. Findings Based on the energy-based approach, atomization occurs because of kinetic energy loss. The resulting formulation reveals that the MDD is inversely proportional to the atomization efficiency and liquid Weber number. Research limitations/implications The results of these three models are compared with the available experimental data. Prediction obtained by the proposed TEB model is in reasonable agreement with the result of experiment. Practical implications The results of these three models are compared with the available experimental data. Prediction of the proposed energy-based theoretical model is in very good agreement with experimental data. Originality/value Comparison between the results of new model, experimental data, other previous methods show that it can be used as a new simple and fast model to achieve good estimation of spray MDD.

Numerical and experimental testing of aircraft tyre impact during landing

2021 ◽  
pp. 1-17
Author(s):  
Y. Gan ◽  
X. Fang ◽  
X. Wei ◽  
H. Nie
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Numerical Models ◽  
Experimental Testing ◽  
Element Model ◽  
Impact Testing ◽  
Tyre Model ◽  
Experimental Database ◽  
The Public ◽  
Landing Impact

Abstract The capability of aircraft tyres to sustain landing impact loads is essential for flight landing safety. Hence, the development of a reliable experimental database is necessary to validate numerical models. The experimental data on aircraft tyre landing impact in the public literature are somewhat sparse. This paper describes a detailed design rig for aircraft tyre impact testing. A finite element model is then created and simulated using a finite element tool (ABAQUS). Inflation and static load simulations are analysed based on the FE tyre model to confirm its reliability. Comparison of experimental measurements with the results reveals that the model can predict the significant features of aircraft tyre impact in a landing scenario. Very little experimental data are publicly available to verify aircraft tyre models. Therefore, the experimental data in this paper fill this gap in the literature.

Identifying Physico-Chemical Laws from the Robotically Collected Data

2019 ◽  
Author(s):  
Liwei Cao ◽  
Danilo Russo ◽  
Vassilios S. Vassiliadis ◽  
Alexei Lapkin
Keyword(s):  
Experimental Data ◽  
Numerical Models ◽  
Predictor Variable ◽  
Physical Models ◽  
Training Data ◽  
Mixed Integer ◽  
Physico Chemical ◽  
Data Points ◽  
Future Work ◽  
The Relationship

<p>A mixed-integer nonlinear programming (MINLP) formulation for symbolic regression was proposed to identify physical models from noisy experimental data. The formulation was tested using numerical models and was found to be more efficient than the previous literature example with respect to the number of predictor variables and training data points. The globally optimal search was extended to identify physical models and to cope with noise in the experimental data predictor variable. The methodology was coupled with the collection of experimental data in an automated fashion, and was proven to be successful in identifying the correct physical models describing the relationship between the shear stress and shear rate for both Newtonian and non-Newtonian fluids, and simple kinetic laws of reactions. Future work will focus on addressing the limitations of the formulation presented in this work, by extending it to be able to address larger complex physical models.</p><p><br></p>

Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column

2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Particle Size ◽  
Adsorption Capacity ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Fungal Biomass ◽  
Solution Flow Rate ◽  
Maximum Adsorption Capacity ◽  
Solution Flow

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

Simulation on Extrusion Comminution Model of Roller Press

2010 ◽  
Vol 156-157 ◽  
pp. 1702-1707
Author(s):  
Xiang Wen Cheng ◽  
Jinchao Liu ◽  
Qi Zhi Ding ◽  
Li Ming Song ◽  
Zhan Lin Wang
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Field Experiments ◽  
Size Ratio ◽  
Optimum Operating ◽  
Extrusion Force ◽  
Particle Size Ratio ◽  
Small Constant ◽  
Working Parameters ◽  
The Relationship

How to predict the relationship among particle size and among product size, to establish the relationship between the granularity and working parameters in the process of grinding and to determine the optimum operating parameters. With proposing BS squeeze crush model by L. Bass and the idea of roll surface division as the material uneven extrusion force are adopted. Based on field experiments the experimental data is analyzed, the select function and the breakage functions are fitted with MATLAB software, and obtaining their model. The comminution model is determined by the roller division. We obtain the model parameter through the experimental data. Through model analysis shows: the relationship between particle breakage and energy absorption, namely the smaller size of the same power, the lower broken; the breakage diminishes with the decrease of particle size ratio and it will be tending to a small constant when the smaller particle size ratio. The breakage functions rapidly decrease within ratio of between 0.2-0.7. This shows: the energy consumption will rapidly increase when the particle size of less than 0.2 in broken; the selection diminish with the decrease of particle size. Pressure (8-9MPa) should be the most appropriate value.

scholarly journals Ambidexterity and organizational learning: revisiting and reconnecting the literatures

2019 ◽  
Vol 26 (4) ◽  
pp. 337-351 ◽  
Author(s):  
Jacob Brix
Keyword(s):  
Organizational Learning ◽  
Absorptive Capacity ◽  
Empirical Data ◽  
Design Methodology ◽  
Organizational Ambidexterity ◽  
Exploration And Exploitation ◽  
Seminal Paper ◽  
Content Type ◽  
New Model ◽  
Multiple Levels

PurposeThe purpose of the study is to investigate how the processes of exploration and exploitation have developed in parallel in the literature of organizational ambidexterity and organizational learning, since James March published his seminal paper in 1991. The goal of the paper is to provide a synthesis of exploration and exploitation based on the two areas of literature.Design/methodology/approachThe study is conceptual and no empirical data have been used.FindingsThe study advances current understanding of exploration and exploitation by building a new model for organizational ambidexterity that takes into account multiple levels of learning, perspectives from absorptive capacity and inter-organizational learning.Originality/valueThe study’s novelty lies in the creation and discussion of a synthesis of exploration and exploitation stemming from organizational ambidexterity and organizational learning.

Numerical Study on the Erosion Characteristics of U-Type Bend for Gas Solid Flow

2017 ◽  
Author(s):  
Yu Wang ◽  
Qi He ◽  
Ming Liu ◽  
Weixiong Chen ◽  
Junjie Yan
Keyword(s):  
Particle Size ◽  
Erosion Rate ◽  
Loading Rate ◽  
Pipe Wall ◽  
Numerical Study ◽  
Pulverized Coal ◽  
Mass Loading ◽  
Two Phase ◽  
Inlet Velocity ◽  
Pipe System

In pulverized coal-fired plant, the U-type bend is commonly used in flue gas and pulverized coal pipe system to due to the constraints of outer space. And gas-solid two-phase flow exists in these pipelines. The erosion of the pipe has significant effect on the safety and reliability of pipelines. In present paper, the erosion characteristics of U-type bend were investigated through CFD (Computational Fluid Dynamics) method. The wear distribution on the pipe wall was obtained. And the particle flow characteristics in U-type bend were analyzed. The influence of inlet velocity, mass loading rate and particle size on the erosion rate was studied as well. Result suggested that the maximum erosion rate increases exponentially with the increase of inlet velocity. And maximum erosion rate increases linearly with the increasing mass loading rate. Increasing particle size can aggravate the wear on the pipe wall.

Effects of Multiple Impacts and Size Distribution of Particles on Erosion Predictions Using CFD

2007 ◽  
Author(s):  
Yongli Zhang ◽  
Brenton S. McLaury ◽  
Siamack A. Shirzai
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Target Material ◽  
Average Particle ◽  
Multiple Impacts ◽  
Cfd Simulations ◽  
Erosion Damage ◽  
Wide Range

Erosion equations are usually obtained from experiments by impacting solid particles entrained in a gas or liquid on a target material. The erosion equations are utilized in CFD (Computational Fluid Dynamics) models to predict erosion damage caused by solid particle impingements. Many erosion equations are provided in terms of an erosion ratio. By definition, the erosion ratio is the mass loss of target material divided by the mass of impacting particles. The mass of impacting particles is the summation of (particle mass × number of impacts) of each particle. In erosion experiments conducted to determine erosion equations, some particles may impact the target wall many times and some other particles may not impact the target at all. Therefore, the experimental data may not reflect the actual erosion ratio because the mass of the sand that is used to run the experiments is assumed to be the mass of the impacting particles. CFD and particle trajectory simulations are applied in the present work to study effects of multiple impacts on developing erosion ratio equations. The erosion equation as well as the CFD-based erosion modeling procedure is validated against a variety of experimental data. The results show that the effect of multiple impacts is negligible in air cases. In water cases, however, this effect needs to be accounted for especially for small particles. This makes it impractical to develop erosion ratio equations from experimental data obtained for tests with sand in water or dense gases. Many factors affecting erosion damage are accounted for in various erosion equations. In addition to some well-studied parameters such as particle impacting speed and impacting angle, particle size also plays a significant role in the erosion process. An average particle size is usually used in analyzing experimental data or estimating erosion damage cases of practical interest. In petroleum production applications, however, the size of sand particles that are entrained in produced fluids can vary over a fairly broad range. CFD simulations are also performed to study the effect of particle size distribution. In CFD simulations, particle sizes are normally distributed with the mean equaling the average size of interest and the standard deviation varying over a wide range. Based on CFD simulations, an equation is developed and can be applied to account for the effect of the particle size distribution on erosion prediction for gases and liquids.

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