The document discusses a PhD project on coupling a population balance model with droplet icing. It begins with context on two-phase flows in oil pipelines and the need to model droplet size distribution and solidification. It presents numerical results validating models for droplet diameter predictions and single-fluid solidification. It concludes that the models show good comparison to experimental data and coupling them could provide more accurate prediction of solidification rates and flow behavior.
Oscillatory flow and particle suspension in a fluid through an elastic tubeAlexander Decker
This document presents a mathematical model for oscillatory flow and particle suspension in a fluid through an elastic tube. It extends an earlier model by Womersley to account for the presence of particles in the fluid (like blood cells in blood flow).
The model considers the fluid phase, particulate phase, and elastic tube wall equations of motion. Assumptions are made about fluid incompressibility, negligible inertia terms, and harmonic pressure waves. Governing equations are derived for both fluid and particulate phases, along with continuity equations.
The frequency equation solution is obtained using Bessel functions. It has a different structure than Womersley's solution due to the added particulate phase. Setting the particle density to zero recovers Womers
This document summarizes a laboratory experiment conducted as part of a "Chemical Engineering Laboratory III" course. The experiment studied pressure drops in two fluid flow systems - a "dark blue circuit" and a "light blue circuit" - which differed in their pipe connections. Students measured the time required to collect 5 kg of water and the corresponding pressure readings. They calculated flow rates, pressure losses, and friction coefficients using the data and equations provided. Plots of log(pressure loss) vs log(flow rate) and Reynolds number vs friction coefficient were created from the results.
Critical analysis of zwietering correlation for solidsfabiola_9
This document provides a critical analysis of limitations in the Zwietering correlation for predicting the just suspended speed (Njs) of solids in stirred tanks. It reviews how factors like particle properties, liquid viscosity, geometry, and scale-up are either not fully captured or have limited ranges of applicability in the Zwietering correlation. New data on the effects of off-bottom clearance and solids concentration show these cannot be explicitly accounted for using the Zwietering equation form and suggest modified exponents are needed for solids concentration above 2% by weight.
Bubble column reactors allow gas and liquid to contact by dispersing gas into the liquid in the form of bubbles. The document discusses bubble column fundamentals, types of bubble columns, gas sparging methods, bubble flow dynamics, CFD modeling techniques, and comparisons of experiments and simulations. It provides details on gas holdup, interphase forces, flow regimes, and strategies for verifying CFD models of bubble columns with experimental data.
This document describes the airlift bioreactor, which uses forced air circulation to mix cells and nutrients without mechanical agitation. It has an inner riser region where air is injected upwards, and an outer downcomer region where degassed media and cells circulate downwards. The density gradient between these regions drives continuous fluid circulation. The bioreactor has a gas separator, sparger, and headspace to introduce air, separate gases, and allow foaming. It is useful for culturing shear-sensitive cells as it provides gentle mixing with low energy use.
The document discusses extractive metallurgy processes for zinc extraction. It describes the major zinc ores and details several pyrometallurgical and hydrometallurgical extraction processes. The key processes are roasting to produce zinc oxide from zinc sulfide ores, followed by leaching and electrolysis to recover zinc. Approximately 80% of zinc is produced via hydrometallurgical routes like roast-leach-electrowinning.
5th International Conference : Workshop - Energyicarb
This document summarizes a meeting about developing consistent methods for accounting carbon emissions from wind power generation. The meeting agenda included presentations on different life cycle carbon assessment approaches, including process-based, cost-based, and hybrid models. Attendees included policymakers, academics, and environmental groups. The meeting aimed to discuss case studies, get feedback on carbon accounting guidelines, and explore applying lessons to other sectors. Presenters also discussed normalizing varied life cycle assessment results and understanding how wind interacts with the electric grid. The document proposes developing a standard framework and accreditation for carbon accounting through the Initiative for Carbon Accounting.
This document summarizes a PhD thesis on modeling two-phase flows of water droplets dispersed in oil and predicting droplet freezing during oil transportation pipelines. It describes developing a population balance model to simulate droplet behavior, single-fluid models to predict ice formation rates, and a multi-fluid model coupling the two. The population balance and single-fluid models were validated against experimental and numerical studies. A partial validation of the multi-fluid model showed similar results to the single-fluid model. Future work will fully validate the multi-fluid model and couple it with the population balance model to predict droplet freezing in two-phase flows.
Oscillatory flow and particle suspension in a fluid through an elastic tubeAlexander Decker
This document presents a mathematical model for oscillatory flow and particle suspension in a fluid through an elastic tube. It extends an earlier model by Womersley to account for the presence of particles in the fluid (like blood cells in blood flow).
The model considers the fluid phase, particulate phase, and elastic tube wall equations of motion. Assumptions are made about fluid incompressibility, negligible inertia terms, and harmonic pressure waves. Governing equations are derived for both fluid and particulate phases, along with continuity equations.
The frequency equation solution is obtained using Bessel functions. It has a different structure than Womersley's solution due to the added particulate phase. Setting the particle density to zero recovers Womers
This document summarizes a laboratory experiment conducted as part of a "Chemical Engineering Laboratory III" course. The experiment studied pressure drops in two fluid flow systems - a "dark blue circuit" and a "light blue circuit" - which differed in their pipe connections. Students measured the time required to collect 5 kg of water and the corresponding pressure readings. They calculated flow rates, pressure losses, and friction coefficients using the data and equations provided. Plots of log(pressure loss) vs log(flow rate) and Reynolds number vs friction coefficient were created from the results.
Critical analysis of zwietering correlation for solidsfabiola_9
This document provides a critical analysis of limitations in the Zwietering correlation for predicting the just suspended speed (Njs) of solids in stirred tanks. It reviews how factors like particle properties, liquid viscosity, geometry, and scale-up are either not fully captured or have limited ranges of applicability in the Zwietering correlation. New data on the effects of off-bottom clearance and solids concentration show these cannot be explicitly accounted for using the Zwietering equation form and suggest modified exponents are needed for solids concentration above 2% by weight.
Bubble column reactors allow gas and liquid to contact by dispersing gas into the liquid in the form of bubbles. The document discusses bubble column fundamentals, types of bubble columns, gas sparging methods, bubble flow dynamics, CFD modeling techniques, and comparisons of experiments and simulations. It provides details on gas holdup, interphase forces, flow regimes, and strategies for verifying CFD models of bubble columns with experimental data.
This document describes the airlift bioreactor, which uses forced air circulation to mix cells and nutrients without mechanical agitation. It has an inner riser region where air is injected upwards, and an outer downcomer region where degassed media and cells circulate downwards. The density gradient between these regions drives continuous fluid circulation. The bioreactor has a gas separator, sparger, and headspace to introduce air, separate gases, and allow foaming. It is useful for culturing shear-sensitive cells as it provides gentle mixing with low energy use.
The document discusses extractive metallurgy processes for zinc extraction. It describes the major zinc ores and details several pyrometallurgical and hydrometallurgical extraction processes. The key processes are roasting to produce zinc oxide from zinc sulfide ores, followed by leaching and electrolysis to recover zinc. Approximately 80% of zinc is produced via hydrometallurgical routes like roast-leach-electrowinning.
5th International Conference : Workshop - Energyicarb
This document summarizes a meeting about developing consistent methods for accounting carbon emissions from wind power generation. The meeting agenda included presentations on different life cycle carbon assessment approaches, including process-based, cost-based, and hybrid models. Attendees included policymakers, academics, and environmental groups. The meeting aimed to discuss case studies, get feedback on carbon accounting guidelines, and explore applying lessons to other sectors. Presenters also discussed normalizing varied life cycle assessment results and understanding how wind interacts with the electric grid. The document proposes developing a standard framework and accreditation for carbon accounting through the Initiative for Carbon Accounting.
This document summarizes a PhD thesis on modeling two-phase flows of water droplets dispersed in oil and predicting droplet freezing during oil transportation pipelines. It describes developing a population balance model to simulate droplet behavior, single-fluid models to predict ice formation rates, and a multi-fluid model coupling the two. The population balance and single-fluid models were validated against experimental and numerical studies. A partial validation of the multi-fluid model showed similar results to the single-fluid model. Future work will fully validate the multi-fluid model and couple it with the population balance model to predict droplet freezing in two-phase flows.
5th International Conference : Angela Druckmanicarb
This document discusses taking a whole systems approach to carbon accounting and avoiding unintended consequences. It presents a typology of unintended consequences including:
1. Knowable and avoidable consequences like inefficient toilets using more water than necessary.
2. Hard to assess consequences like the increased emissions from indirect land use change due to biofuels leading to deforestation.
3. "Knowable" but unavoidable consequences like rebound effects where improvements in energy efficiency lead to increased rather than decreased energy use through things like driving more or heating larger homes.
This document outlines a computational fluid dynamics (CFD) analysis of gas flow in high permeability hydraulically fractured horizontal wells. The research objectives are to develop a 3D CFD model to compare production from plug-and-perf and open hole multi-stage completions, and to model transverse and longitudinal fractures. The methodology includes validating existing horizontal well models, developing single and dual transverse fracture models, and simulating the models under varying parameters. Production is compared between completions and fracture orientations through steady-state simulations while varying factors like fracture width, penetration ratio, and permeability anisotropy.
Ab experiments of fluid flow in polymer microchannelShaelMalik
1) The document discusses a computational fluid dynamics (CFD) study of droplet formation in a microfluidic cross-junction when the dispersed phase is a non-Newtonian fluid.
2) Simulations were performed using OpenFOAM to model droplet formation of xanthan gum solutions (shear thinning) in canola oil (Newtonian) across varying xanthan concentrations.
3) The results show that increasing the xanthan concentration leads to longer thread detachment times, wider thread widths at the junction entrance, and smaller dimensionless droplet diameters, demonstrating the impact of shear thinning behavior on droplet formation.
Javier Garcia - Verdugo Sanchez - Six Sigma Training - W2 Multi - vari StudiesJ. García - Verdugo
This document discusses procedures for conducting and analyzing multivariable studies. It begins by providing an overview and explaining that multivariable studies examine how multiple factors interact and influence process outputs. The document then discusses planning a study, collecting data, analyzing the data, and reporting results. It provides an example study looking at contamination levels and examines the effects of factors like day, shift, and time using tools like ANOVA. The results indicate shift has a significant impact on contamination levels.
Analysis of convection diffusion problems at various peclet numbers using fin...Alexander Decker
This document summarizes research analyzing convection-diffusion problems at various Peclet numbers using finite volume and finite difference schemes. It introduces convection-diffusion equations, defines Peclet number, and describes how central differencing and upwind differencing schemes were used to discretize and solve sample convection-diffusion problems numerically. The results show that central differencing leads to inaccurate solutions at high Peclet numbers, while upwind differencing satisfies consistency criteria by accounting for flow direction.
Diffuse and localized necking under plane stress in visco-plastic material mo...Salvatore Scalera
In a tension test on a ductile material, a diffuse necking - so called because its spatial extension is much larger than the sheet thickness - begins to develop in the sample when the strain hardening is no longer able to compensate for the weakening due to the reduction of the cross section. After some elongation under decreasing load, a localized neck usually appears in the region of the diffuse neck. In the localized neck, severe thinning occurs leading to ultimate failure.
This work focuses on studying the diffuse and localized necking under plane stress conditions in visco-plastic materials under dynamic loading. By means of a DOE analysis the main material parameters that influence the occurrence of local and diffuse necking were determined. A material model is then validated by systematic comparison of simulation results with physical tests carried out at different strain rates. One methodology to achieve good correlation between test and experiments is the use of a damage model. The damage model chosen by the authors is GISSMO (Generalized Incremental Stress-State dependent damage Model), due to its widespread usage in the crash community.
The GISSMO model is defined in terms of a critical plastic strain that indicates the start of damage coupling and a failure plastic strain indicating fracture, both are defined as a function of stress triaxiality. As the necking or more generally plastic instability will result in mesh dependency of the simulation results, regularization is introduced by defining both the failure plastic strain and the damage exponent as a function of the mesh size. As the spatial extension of the diffuse neck differs as a function of strain rate, one way to achieve correlation between test and simulation is to express these parameters as function of both the mesh size and the strain rate.
As consequence of the findings of this study, a number of new options were developed in the GISSMO model.
Prof Graeme Dandy at the Landscape Science Cluster Seminar, May 2009pdalby
Professor Graeme Dandy from the University of Adelaide presenting on Optimisation of Water Management at the Landscape Science Cluster Seminar, May 2009
Field Monitoringfor Lulucf Projects Tim Pearson Bio C Fplus Iiwrcinashfield
The document provides guidance on field monitoring for land use, land-use change and forestry (LULUCF) projects to measure carbon stock changes. It discusses defining project boundaries, stratifying the project area, deciding which carbon pools to measure, developing sampling designs, and determining measurement frequency. Accuracy and precision in monitoring are important to achieve.
Presentation to the UK Climate Projections event for the third sector at Defra's Innovation Centre, Reading on 28 July 2009.
Dr Alastair Brown
UK Climate Impacts Programme (UKCIP)
Presentation by Dr Alastair Brown (UK Climate Impacts Programme - UKCIP) to the third sector event on the UK Climate Projections tools.
Defra's Innovation Centre
Reading
28 July 2009
2008 IFAC World Congress: Oil and gas production optimization - lost potentia...Steinar Elgsæter
The information content in measurements of offshore oil and gas production is often low, and when a production model is fitted to such data, uncertainty may result. If production is optimized with an uncertain model, some potential production profit may be lost. The costs and risks of introducing additional excitation are typically large and cannot be justified unless the potential increase in profits are quantified. In previous work it is discussed how bootstrapping can be used to estimate uncertainty resulting from fitting production models to data with low information content. In this paper we propose how lost potential resulting from estimated uncertainty can be estimated using Monte-Carlo analysis. Based on a conservative formulation of the production optimization problem, a potential for production optimization in excess of 2% and lost potential due to the form of uncertainty considered in excess of 0.5% was identified using field data from a North Sea field.
Determination of shock losses and pressure losses in ug mine openingsSafdar Ali
This document discusses determining pressure and shock losses in underground mine openings using computational fluid dynamics (CFD) simulation techniques. It aims to calculate losses in different mine configurations using CFD and compare results to classical formulas. The document outlines the objective, scope, literature review on losses, and CFD methodology. It describes setting up simulations of common mine geometries like tunnels, bends, junctions, and shafts in Gambit meshing software and analyzing them in Fluent. Results are presented on velocity profiles and pressure losses for configurations like gradual contractions and expansions.
Determination of shock losses and pressure losses in ug mine openings (1)Safdar Ali
This document discusses the determination of shock and pressure losses in underground mine openings using computational fluid dynamics (CFD) simulation techniques. The objective is to calculate losses in different mine configurations and compare results from CFD simulations to classical formulas. The document outlines the scope of the project, literature review on losses, and describes meshing mine geometries in Gambit and performing CFD simulations in Fluent. Results are presented for simulations of tunnels, bends, junctions, contractions, expansions, shafts, and regulators. CFD-generated shock loss coefficients are found to agree reasonably well with published values, except for splits/junctions and forcing shafts, which may be due to modeling limitations. The conclusion is that 3D
Dr Steve Allen, Sustain Ltd and Dr Marcelle McManus of the University of Bath set out the thinking and research behind conducting Life Cycle Assessment and the business benefits of carrying it out.
Speakers: Shardul Agrawala, Head of Environment and Economy Integration Division (OECD) and Elisa Lanzi, Senior Economist (OECD).
Presentation at the 1st meeting of the Working Party on Climate Change (WPCC) held at the OECD headquarters on 27-28 September, 2023.
This is a presentation of the state of play of Climate Adaptation Marker Quality Review, created by Valérie Gaveau from the OECD DCD Secretariat, presented at the DAC 15th ENVIRONET Workshop on Climate Finance in Paris. For more information, please contact Stephanie Ockenden (stephanie.ockenden@oecd.org).
Javier Garcia - Verdugo Sanchez - Six Sigma Training - W4 Monte Carlo Simulat...J. García - Verdugo
This document describes using Monte Carlo simulation to analyze variations in manufacturing processes and electrical circuits. It discusses generating random input variables based on their distributions, calculating output results using equations, and analyzing the output distribution to determine process capability and variation. An example simulates variations in five stacked metal parts and calculates the total dimension distribution. Another simulates variations in resistor values in an electrical circuit and calculates the distribution of the output voltage.
This document summarizes a study on optimizing the hull shape and dimensions of a point absorber wave energy converter. The study aimed to derive an efficient design for the buoy and improve the physical modeling of the device's response to waves. Different shapes and dimensions were evaluated in a frequency domain model and the most efficient design was selected for further time domain modeling and analysis, which included parameterizing drag coefficients obtained from computational fluid dynamics simulations. The improved time domain model was validated against simulation results and found to increase the physical accuracy of modeling viscous effects.
A Comprehensive Study of Multiphase Flow through Annular Pipe using CFD ApproachRaian Nur Islam
This study analyzes 3D fluid flow through the annular pipeline with multiphase fluids using CFD simulation. Eulerian Model with Reynolds Stress Model (RSM) turbulence closure is adopted to analyze multiphase fluid flow. The results are validated with existing experimental data and empirical correlations. A robust simulation model is developed that can be used further for different applied cases. Geometry and boundary conditions of flow are adopted from experimental works to validate the simulation. The sensitivity analysis is also conducted to observe the flow characteristics. Fluid inlet velocity of distinct phases, inner pipe rotation and eccentricity are used as input or independent parameters and pressure gradient and local concentration profile at different sections of geometry are the primary output parameter to analyze. The key results show that changing inner pipe rotation and eccentricity have a significant impact on output pressure and local particle distribution which eventually help to find a way out from particle blockage. This study would help the oil and gas industry in designing their pipelines.
5th International Conference : Angela Druckmanicarb
This document discusses taking a whole systems approach to carbon accounting and avoiding unintended consequences. It presents a typology of unintended consequences including:
1. Knowable and avoidable consequences like inefficient toilets using more water than necessary.
2. Hard to assess consequences like the increased emissions from indirect land use change due to biofuels leading to deforestation.
3. "Knowable" but unavoidable consequences like rebound effects where improvements in energy efficiency lead to increased rather than decreased energy use through things like driving more or heating larger homes.
This document outlines a computational fluid dynamics (CFD) analysis of gas flow in high permeability hydraulically fractured horizontal wells. The research objectives are to develop a 3D CFD model to compare production from plug-and-perf and open hole multi-stage completions, and to model transverse and longitudinal fractures. The methodology includes validating existing horizontal well models, developing single and dual transverse fracture models, and simulating the models under varying parameters. Production is compared between completions and fracture orientations through steady-state simulations while varying factors like fracture width, penetration ratio, and permeability anisotropy.
Ab experiments of fluid flow in polymer microchannelShaelMalik
1) The document discusses a computational fluid dynamics (CFD) study of droplet formation in a microfluidic cross-junction when the dispersed phase is a non-Newtonian fluid.
2) Simulations were performed using OpenFOAM to model droplet formation of xanthan gum solutions (shear thinning) in canola oil (Newtonian) across varying xanthan concentrations.
3) The results show that increasing the xanthan concentration leads to longer thread detachment times, wider thread widths at the junction entrance, and smaller dimensionless droplet diameters, demonstrating the impact of shear thinning behavior on droplet formation.
Javier Garcia - Verdugo Sanchez - Six Sigma Training - W2 Multi - vari StudiesJ. García - Verdugo
This document discusses procedures for conducting and analyzing multivariable studies. It begins by providing an overview and explaining that multivariable studies examine how multiple factors interact and influence process outputs. The document then discusses planning a study, collecting data, analyzing the data, and reporting results. It provides an example study looking at contamination levels and examines the effects of factors like day, shift, and time using tools like ANOVA. The results indicate shift has a significant impact on contamination levels.
Analysis of convection diffusion problems at various peclet numbers using fin...Alexander Decker
This document summarizes research analyzing convection-diffusion problems at various Peclet numbers using finite volume and finite difference schemes. It introduces convection-diffusion equations, defines Peclet number, and describes how central differencing and upwind differencing schemes were used to discretize and solve sample convection-diffusion problems numerically. The results show that central differencing leads to inaccurate solutions at high Peclet numbers, while upwind differencing satisfies consistency criteria by accounting for flow direction.
Diffuse and localized necking under plane stress in visco-plastic material mo...Salvatore Scalera
In a tension test on a ductile material, a diffuse necking - so called because its spatial extension is much larger than the sheet thickness - begins to develop in the sample when the strain hardening is no longer able to compensate for the weakening due to the reduction of the cross section. After some elongation under decreasing load, a localized neck usually appears in the region of the diffuse neck. In the localized neck, severe thinning occurs leading to ultimate failure.
This work focuses on studying the diffuse and localized necking under plane stress conditions in visco-plastic materials under dynamic loading. By means of a DOE analysis the main material parameters that influence the occurrence of local and diffuse necking were determined. A material model is then validated by systematic comparison of simulation results with physical tests carried out at different strain rates. One methodology to achieve good correlation between test and experiments is the use of a damage model. The damage model chosen by the authors is GISSMO (Generalized Incremental Stress-State dependent damage Model), due to its widespread usage in the crash community.
The GISSMO model is defined in terms of a critical plastic strain that indicates the start of damage coupling and a failure plastic strain indicating fracture, both are defined as a function of stress triaxiality. As the necking or more generally plastic instability will result in mesh dependency of the simulation results, regularization is introduced by defining both the failure plastic strain and the damage exponent as a function of the mesh size. As the spatial extension of the diffuse neck differs as a function of strain rate, one way to achieve correlation between test and simulation is to express these parameters as function of both the mesh size and the strain rate.
As consequence of the findings of this study, a number of new options were developed in the GISSMO model.
Prof Graeme Dandy at the Landscape Science Cluster Seminar, May 2009pdalby
Professor Graeme Dandy from the University of Adelaide presenting on Optimisation of Water Management at the Landscape Science Cluster Seminar, May 2009
Field Monitoringfor Lulucf Projects Tim Pearson Bio C Fplus Iiwrcinashfield
The document provides guidance on field monitoring for land use, land-use change and forestry (LULUCF) projects to measure carbon stock changes. It discusses defining project boundaries, stratifying the project area, deciding which carbon pools to measure, developing sampling designs, and determining measurement frequency. Accuracy and precision in monitoring are important to achieve.
Presentation to the UK Climate Projections event for the third sector at Defra's Innovation Centre, Reading on 28 July 2009.
Dr Alastair Brown
UK Climate Impacts Programme (UKCIP)
Presentation by Dr Alastair Brown (UK Climate Impacts Programme - UKCIP) to the third sector event on the UK Climate Projections tools.
Defra's Innovation Centre
Reading
28 July 2009
2008 IFAC World Congress: Oil and gas production optimization - lost potentia...Steinar Elgsæter
The information content in measurements of offshore oil and gas production is often low, and when a production model is fitted to such data, uncertainty may result. If production is optimized with an uncertain model, some potential production profit may be lost. The costs and risks of introducing additional excitation are typically large and cannot be justified unless the potential increase in profits are quantified. In previous work it is discussed how bootstrapping can be used to estimate uncertainty resulting from fitting production models to data with low information content. In this paper we propose how lost potential resulting from estimated uncertainty can be estimated using Monte-Carlo analysis. Based on a conservative formulation of the production optimization problem, a potential for production optimization in excess of 2% and lost potential due to the form of uncertainty considered in excess of 0.5% was identified using field data from a North Sea field.
Determination of shock losses and pressure losses in ug mine openingsSafdar Ali
This document discusses determining pressure and shock losses in underground mine openings using computational fluid dynamics (CFD) simulation techniques. It aims to calculate losses in different mine configurations using CFD and compare results to classical formulas. The document outlines the objective, scope, literature review on losses, and CFD methodology. It describes setting up simulations of common mine geometries like tunnels, bends, junctions, and shafts in Gambit meshing software and analyzing them in Fluent. Results are presented on velocity profiles and pressure losses for configurations like gradual contractions and expansions.
Determination of shock losses and pressure losses in ug mine openings (1)Safdar Ali
This document discusses the determination of shock and pressure losses in underground mine openings using computational fluid dynamics (CFD) simulation techniques. The objective is to calculate losses in different mine configurations and compare results from CFD simulations to classical formulas. The document outlines the scope of the project, literature review on losses, and describes meshing mine geometries in Gambit and performing CFD simulations in Fluent. Results are presented for simulations of tunnels, bends, junctions, contractions, expansions, shafts, and regulators. CFD-generated shock loss coefficients are found to agree reasonably well with published values, except for splits/junctions and forcing shafts, which may be due to modeling limitations. The conclusion is that 3D
Dr Steve Allen, Sustain Ltd and Dr Marcelle McManus of the University of Bath set out the thinking and research behind conducting Life Cycle Assessment and the business benefits of carrying it out.
Speakers: Shardul Agrawala, Head of Environment and Economy Integration Division (OECD) and Elisa Lanzi, Senior Economist (OECD).
Presentation at the 1st meeting of the Working Party on Climate Change (WPCC) held at the OECD headquarters on 27-28 September, 2023.
This is a presentation of the state of play of Climate Adaptation Marker Quality Review, created by Valérie Gaveau from the OECD DCD Secretariat, presented at the DAC 15th ENVIRONET Workshop on Climate Finance in Paris. For more information, please contact Stephanie Ockenden (stephanie.ockenden@oecd.org).
Javier Garcia - Verdugo Sanchez - Six Sigma Training - W4 Monte Carlo Simulat...J. García - Verdugo
This document describes using Monte Carlo simulation to analyze variations in manufacturing processes and electrical circuits. It discusses generating random input variables based on their distributions, calculating output results using equations, and analyzing the output distribution to determine process capability and variation. An example simulates variations in five stacked metal parts and calculates the total dimension distribution. Another simulates variations in resistor values in an electrical circuit and calculates the distribution of the output voltage.
This document summarizes a study on optimizing the hull shape and dimensions of a point absorber wave energy converter. The study aimed to derive an efficient design for the buoy and improve the physical modeling of the device's response to waves. Different shapes and dimensions were evaluated in a frequency domain model and the most efficient design was selected for further time domain modeling and analysis, which included parameterizing drag coefficients obtained from computational fluid dynamics simulations. The improved time domain model was validated against simulation results and found to increase the physical accuracy of modeling viscous effects.
A Comprehensive Study of Multiphase Flow through Annular Pipe using CFD ApproachRaian Nur Islam
This study analyzes 3D fluid flow through the annular pipeline with multiphase fluids using CFD simulation. Eulerian Model with Reynolds Stress Model (RSM) turbulence closure is adopted to analyze multiphase fluid flow. The results are validated with existing experimental data and empirical correlations. A robust simulation model is developed that can be used further for different applied cases. Geometry and boundary conditions of flow are adopted from experimental works to validate the simulation. The sensitivity analysis is also conducted to observe the flow characteristics. Fluid inlet velocity of distinct phases, inner pipe rotation and eccentricity are used as input or independent parameters and pressure gradient and local concentration profile at different sections of geometry are the primary output parameter to analyze. The key results show that changing inner pipe rotation and eccentricity have a significant impact on output pressure and local particle distribution which eventually help to find a way out from particle blockage. This study would help the oil and gas industry in designing their pipelines.
1. Context Numerical results Conclusion
Coupling of a population balance model with
droplet deposition, entrainment and icing
Arnaud Bourdillon
School of Energy, Environment & Agrifood
Oil & Gas Engineering centre Cranfield University
November 3, 2015
2. Context Numerical results Conclusion
Outline
1 Context of the project
General field of study
Specific field of study
Specific problems of the area
Limitations of the current methods
Objectives of this PhD
2 Numerical results
Droplet diameter predictions
Single-fluid solidification solver
Multi-fluid solidification solver
3 Conclusion and future work
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 1 / 29
3. Context Numerical results Conclusion General area Specific area Problem Limitations Objectives
General field of study
Oil industry
Pumping of oil through pipelines
Substances pumped
Oil, water, gas, sand...
Induce complex phenomena
Mixing, deposition, separation...
Industry concerns
Life time, efficiency...
Measurable by knowledge of
Velocities, temperatures,
pressures...
Obtained by
Experiments or numerical
simulations (CFD) Alaska pipeline [1]
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 2 / 29
4. Context Numerical results Conclusion General area Specific area Problem Limitations Objectives
Specific field of study
Two-phase flows
Water and oil
Interaction between phases
Water droplets transported by oil
Motion of droplets
Drag, lift, virtual mass...
Distribution of droplets
Population balance modelling
Size and shape of droplets
Break-up and coalescence
Necessary to
Accurately describe the flow
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 3 / 29
5. Context Numerical results Conclusion General area Specific area Problem Limitations Objectives
Specific problems of the area
Pipes in extreme conditions
Cold weather, deep water...
Regions of interest
Internal regions
Consequences
Erosion, corrosion...
Solidification (icing)...
Can induce
Blocking, breakage of the pipe...
Pipe in extreme condition [2]
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 4 / 29
6. Context Numerical results Conclusion General area Specific area Problem Limitations Objectives
Limitations of the current methods
Size, shape and distribution of droplets
Validated models in the literature
Droplets distribution: Population balance modelling
Monte-Carlo [18], method of classes [8], method of moments [9],
quadrature method of moments [13], extended quadrature
method of moments [3]....
Droplets size and shape changes
Break-up and coalescence models [10], [11]
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 5 / 29
7. Context Numerical results Conclusion General area Specific area Problem Limitations Objectives
Limitations of the current methods
Size, shape and distribution of droplets
Validated models in the literature
Droplets distribution: Population balance modelling
Monte-Carlo [18], method of classes [8], method of moments [9],
quadrature method of moments [13], extended quadrature
method of moments [3]....
Droplets size and shape changes
Break-up and coalescence models [10], [11]
Solidification of a phase
Validated models in the literature
Phase solidification: Icing models
Apparent heat capacity [7], source-based [17], enthalpy-porosity
methods [16] ...
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 5 / 29
8. Context Numerical results Conclusion General area Specific area Problem Limitations Objectives
Limitations of the current methods
What can be done ?
Droplet size, shape and deposition
prediction
Solidification rate prediction
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 6 / 29
9. Context Numerical results Conclusion General area Specific area Problem Limitations Objectives
Limitations of the current methods
What can be done ?
Droplet size, shape and deposition
prediction
Solidification rate prediction
What cannot be done ?
Influence of droplet size, shape
and deposition to the
solidification rate
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 6 / 29
10. Context Numerical results Conclusion General area Specific area Problem Limitations Objectives
Limitations of the current methods
What can be done ?
Droplet size, shape and deposition
prediction
Solidification rate prediction
What cannot be done ?
Influence of droplet size, shape
and deposition to the
solidification rate
What could it bring ?
More accurate solidification rate
More accurate blocking length
Better flow prediction
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 6 / 29
11. Context Numerical results Conclusion General area Specific area Problem Limitations Objectives
Objectives of this PhD
Solidification solver
Develop a 3D, turbulent, transient and multi-fluid solver in
OpenFoam
Population balance solver
Develop a population balance model, along with break-up and
coalescence models in OpenFoam
Coupling population balance and solidification
Develop a coupling between the two previous models in
OpenFoam
Possibly extend further the model
To handle hydrates formation and corrosion-erosion.
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 7 / 29
12. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Eulerian model for droplet diameter: Validation case
Phases α ρ µ u
water 0.062 1166 0.0016 0.158
Kerosene 0.938 797 0.0018 2.398
Test case from literature
Numerical simulation: [12]
Experiments: [4].
Initial condition
Water drops injected at the inlet
(ddrop = 1mm)
Objective
Evaluate mean diameter of
droplets, transported by
kerosene, at the outlet
Mathematical models tested
Population balance modelling
(MOM), break-up and
coalescence models
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 8 / 29
13. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Interphase force effect
FD
, Ftd
FD
, Ftd
, Fvm
FD
, Ftd
, Fℓ
FD
, Ftd
, Fℓ
, Fvm
Verticalposition[m]
−0.03
−0.02
−0.01
0
0.01
0.02
0.03
Sauter mean diameter [μ m]
300 400 500 600 700 800
Outlet top region
Lift force enhances break-up
Outlet bottom region
4 forces slightly increase
maximum droplet diameter
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 9 / 29
14. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Turbulence modelling of the dispersed phase
2-layer k-ε model
Efficient for intermediate
meshes (y+ 4)
Turbulence response model
Predicts velocity of droplets,
based on velocity of oil
Ct =
µd
µc
Discussion
Issa under-predict k rate
⇒ larger droplets (closer to
experimental data)
Issa and Oliveira
Realizable 2-layer k-ɛ
Verticalposition[m]−0.03
−0.02
−0.01
0
0.01
0.02
0.03
Sauter mean diameter [μ m]
300 400 500 600 700 800 900 1000
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 10 / 29
15. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Critical diameter value
Wecrit
= 0.05
Wecrit
= 0.15
Wecrit
= 0.25
Verticalposition[m]
−0.03
−0.02
−0.01
0
0.01
0.02
0.03
Sauter mean diameter [μ m]
200 400 600 800 1000
Critical diameter value
Diameter past which break-up
Formulation
dcrit = 5.6
2σWecrit
ρc
3/5
ε−2/5
Interpretation
Wecrit ⇒ dcrit
dcrit ⇒ Brup rate
Brup rate ⇒ dmean
Discussion
Wecrit linked to coalescence
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 11 / 29
16. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Validation of the study
Simmons & Azzopardi (2001)
Lo & Rao (2007)
Present simulations
Cummulativevolumefraction[-]
0
0.2
0.4
0.6
0.8
1
Sauter mean diameter [μ m]
0 200 400 600 800 1000
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 12 / 29
17. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Conclusion the study
Validation of the study
Good comparison with experimental data for 0.5 < αd < 1
Larger discrepancies with experimental data for 0 < αd < 0.5
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 13 / 29
18. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Conclusion the study
Validation of the study
Good comparison with experimental data for 0.5 < αd < 1
Larger discrepancies with experimental data for 0 < αd < 0.5
Conclusion of the study
Interphase forces of great importance
Turbulence modelling of great importance
Break-up model probably needs further enhancement
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 13 / 29
19. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Conclusion the study
Validation of the study
Good comparison with experimental data for 0.5 < αd < 1
Larger discrepancies with experimental data for 0 < αd < 0.5
Conclusion of the study
Interphase forces of great importance
Turbulence modelling of great importance
Break-up model probably needs further enhancement
Further studies
Similar standard method of moment have been implemented in
OpenFOAM recently [15]
Solver to be enhanced by the previous findings
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 13 / 29
20. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Single-fluid solidification solver: Validation case
Phases λ ρ T[K]
water 0.56 999.8 Tliq = 273.3
Ice 2.26 916.8 Tsol = 273.0
Cylinder D Ti Tcold
82.8 mm 21◦C −18◦C
Test case from literature
Experiments: [6]
Present numerical simulations:
OpenFoam
Initial conditions
Cylinder filled with water at 21◦
C.
Walls are cooled down at −18◦
C
Objective
Compute phase change of water
from liquid to solid
Mathematical models tested
Solidification (enthalpy-porosity)
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 14 / 29
21. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Solidification solver: Formulation
Enthalpy based model
∂ρH
∂t
+ u
∂ρH
∂x
+ v
∂ρH
∂y
= λ∆T
H = h + ∆H ⇒ H =
T
Tref
cpdT + α L
Energy equation
∂ρcpT
∂t
+ u
∂ρcpT
∂x
+ v
∂ρcpT
∂y
= λ∆T + St
St = −L
∂ρα
∂t
+ u
∂ρα
∂x
+ v
∂ρα
∂y
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 15 / 29
22. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Solidification solver: Formulation
Momentum equation
∂ρu
∂t
+ u
∂ρu
∂x
+ v
∂ρu
∂y
= −
∂p
∂x
+ µ∆u − Smx
∂ρv
∂t
+ u
∂ρv
∂x
+ v
∂ρv
∂y
= −
∂p
∂y
+ µ∆v − g[ρ(T) − ρ] − Smy
Mushy region
Smx = FmDc
α2
s
α3 + ε
u
Smy = FmDc
α2
s
α3 + ε
v
Fm = 0.5 +
arctan[cs(αs − αscrit
)]
π
Slurry region
µ =
µ αs = 0 ⇒ liquid region
µ 1 −
Fs
A
−2
αs ≤ αcrit and αs = 0 ⇒ slurry region
µ α + µsαs αs > αcrit and αs = 1 ⇒ mushy region
µs αs = 1 ⇒ solid region
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 16 / 29
23. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Validation of single-fluid solidification
a) Ice layer at t = 500 s
b) Temperature at t = 500 s
c) Ice layer at t = 750 s
d) Temperature at t = 750 s
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 17 / 29
24. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Validation of single-fluid solidification
Experimental (Chen & Lee (1998))
IcingFoam
IcingFoamSlurryMushy
Temperature[○
C]
−15
−10
−5
0
5
10
15
20
Time [s]
0 1000 2000 3000 4000 5000
a) Top part
Experimental (Chen & Lee (1998))
IcingFoam
IcingFoamSlurryMushy
Temperature[○
C]
−15
−10
−5
0
5
10
15
20
Time [s]
0 1000 2000 3000 4000 5000
b) Centre part
Experimental (Chen & Lee (1998))
IcingFoam
IcingFoamSlurryMushy
Temperature[○
C]
−15
−10
−5
0
5
10
15
20
Time [s]
0 1000 2000 3000 4000 5000
c) Side part
Experimental (Chen & Lee (1998))
IcingFoam
IcingFoamSlurryMushy
Temperature[○
C]
−15
−10
−5
0
5
10
15
20
Time [s]
0 1000 2000 3000 4000 5000
d) Bottom part
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 18 / 29
25. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Conclusion of the study
Validation of the study
Good comparison with [6] experimental solution
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 19 / 29
26. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Conclusion of the study
Validation of the study
Good comparison with [6] experimental solution
Discussion
Both slurry and mushy solver give similar results
Slight discrepancies with experiments are due to differences in
operating conditions
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 19 / 29
27. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Conclusion of the study
Validation of the study
Good comparison with [6] experimental solution
Discussion
Both slurry and mushy solver give similar results
Slight discrepancies with experiments are due to differences in
operating conditions
Further and current studies
Solver enhanced to a 3D, turbulent and multi-fluid solidification
flow solver
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 19 / 29
28. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Multi-fluid solver: Validation case
Phases λ ρ T
water 0.6 999.8 Tliq = 273.3
Ice 2.26 916.8 Tsol = 273
cube L = Thot Tcold
38 mm 283 − 278 263
Test case from literature
Experiments: [14].
Present simulations with
OpenFOAM multi-fluid
solidification solver.
Objective
Predict ice-layer growth rate.
Compare results with
experiments of [14].
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 20 / 29
29. Context Numerical results Conclusion Droplet diameter predictions Single-fluid Multi-Fluid
Validation of multi-fluid solidification
Experimental (Kowaleski & Cybulski)
IcingMultiPhaseFoam (fs = 0.5)
Icelayerheight[-]
0.01
0.1
Time [s]
500 1000 1500 2000 2500 3000
a) Results (Thot = 5◦
C)
Experimental (Kowaleski & Cybulski)
IcingMultiPhaseFoam (fs = 0.5)
Icelayerheight[-]
0.01
0.1
Time [s]
400 600 800 1000 1200
b) Results (Thot = 10◦
C)
c) Temperature iso-contour (t = 1800 s)
d) Velocity and ice-layer (t = 1800 s)
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 21 / 29
30. Context Numerical results Conclusion
Conclusion
Conclusion of this work
Droplet motions, size and shape changes have been validated
Parameters influencing droplets behaviour have been analysed
Single-fluid solidification solvers have been validated
Multi-fluid solidification solver has been validated
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 22 / 29
31. Context Numerical results Conclusion
Conclusion
Conclusion of this work
Droplet motions, size and shape changes have been validated
Parameters influencing droplets behaviour have been analysed
Single-fluid solidification solvers have been validated
Multi-fluid solidification solver has been validated
Current and future work
Coupling between PBM and multi-fluid solidification solvers
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 22 / 29
32. Context Numerical results Conclusion
Conclusion
Conclusion of this work
Droplet motions, size and shape changes have been validated
Parameters influencing droplets behaviour have been analysed
Single-fluid solidification solvers have been validated
Multi-fluid solidification solver has been validated
Current and future work
Coupling between PBM and multi-fluid solidification solvers
Further possible extension of this work
Application of the solver to hydrates and errosion/corrosion
problems.
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 22 / 29
33. Context Numerical results Conclusion
Comparison with experiments for ice formation in cavities
a) Experiments [14] (t = 2600 s) b) Present solver (t = 2600 s)
Thank you, any questions ?
Complete work
Bourdillon.A.C, Verdin.P.G and Thompson.C.P. Numerical simulations of water freezing processes in
cavities and cylindrical enclosures. Applied Thermal Engineering, 75, January 2015, 839-855.
Bourdillon.A.C, Verdin.P.G and Thompson.C.P. Numerical simulations of drop size evolution in a horizontal
pipeline. International Journal Of Multiphase Flow, 78, January 2016, 44-58.
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 23 / 29
34. Context Numerical results Conclusion
References I
Google image: dict.space.4goo.net/dict=pipeline.
Google image:
http : //www.filemagazine.com/thecollection/
archives/2007/01/pipelineofd re.html.
Computational models for polydispersed particulate and
multiphase systems.
Cambridge, 2013.
Azzopardi.B and Simmons.M.
Drop size distributions in dispersed liquid-liquid pipe flow.
International Journal of Multiphase Flow, 27, 2001.
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 24 / 29
35. Context Numerical results Conclusion
References II
Bourdillon.A, Verdin.P, and Thompson.C.
Numerical simulations of water freezing processes in
cavities and cylindrical enclosures.
Applied thermal engineering, 75, 2015.
Chen.S and Lee.T.
A study of supercooling phenomenon and freezing
probability of water inside horizontal cylinder.
International Journal of Heat and Mass Transfer, 41, 1998.
Hashemi.H and Sliepcevich.C.
A numerical method for solving two-dimensional problems
of heat conduction with change of phase.
Chemical Engineering Progress, 1967.
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 25 / 29
36. Context Numerical results Conclusion
References III
Hounslow.M, Ryall.R, and Marshall.V.
A discretized population balance for nucleation, growth and
aggregation.
Alche journal, 1988.
Hulburt.H and Katz.S.
Some problems in particle technology- statistical
mechanical formulation.
Chemical Engineering and Science, 1964.
Liao.Y and Lucas.D.
A literature review of theoretical models for drop and bubble
breakup in turbulent dispersions.
Chemical engineering science, 2009.
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 26 / 29
37. Context Numerical results Conclusion
References IV
Liao.Y and Lucas.D.
A literature review on mechanisms and models for the
coalescence process of fluid particles.
Chemical engineering science, 2010.
Lo.S and Rao.P.
Modelling of droplet breakup and coalescence in an
oil-water pipeline.
International Conference on Multiphase Flow, 13, 2007.
McGraw.R.
Description of aerosol dynamics by the quadrature method
of moments.
Aerosol science and technology, 27, 1997.
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 27 / 29
38. Context Numerical results Conclusion
References V
Michalek.T and Kowaleski.A.
Simulations of the water freezing process - numerical
benchmarks.
International Journal of computational fluid dynamics, 2002.
Traczyk.M.
Numerical computations of liquid-liquid dispersions at high
phase fractions.
PhD thesis, Cranfield university, 2014.
Voller.V and Prakash.C.
A fixed grid numerical modelling methodology for
convection-diffusion mushy region phase-change problems.
Heat and mass transfer, 1987.
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 28 / 29
39. Context Numerical results Conclusion
References VI
Voller.V and Swaminathan.C.
General source based method for solidification phase
change.
Numerical Heat Transfer, 1991.
Zhao.H, Kruis.F, and Zheng.C.
A differentially weighted monte carlo method for
two-component coagulation.
Journal of computational physics, 2010.
Coupling of a population balance model with droplet icing - A.C.Bourdillon November 3, 2015 29 / 29