This document provides an overview and summary of a book titled "Slurry Transport: Fundamentals, Historical Overview & The Delft Head Loss & Limit Deposit Velocity Framework". The book was written by Dr.ir. Sape A. Miedema and edited by Robert C. Ramsdell. It covers the fundamentals of horizontal transport of settling slurries in pipelines and develops theoretical models for different flow regimes based on constant volumetric spatial concentration. A new model is presented for the Limit Deposit Velocity and derivation of relationships for pressure loss, concentration distribution, and bed height as a function of line speed. The book is based on experimental data and aims to mathematically describe physical processes involved in slurry transportation.
(Fluid Mechanics and Its Applications 57) Victor Ya. Shkadov, Gregory M. Siso...DavidN26
(Fluid Mechanics and Its Applications 57) Victor Ya. Shkadov, Gregory M. Sisoev (auth.), H.-C. Chang (eds.) - IUTAM Symposium on Nonlinear Waves in Multi-Phase Flow_ Proceedings of the IUTAM Symposium.pdf
This document discusses using genetic programming to determine the most effective parameters that influence scour depth at seawalls. Previous studies have developed equations to predict scour depth but they considered a limited number of parameters and had uncertainties. The genetic programming approach was able to evolve models that identify the most significant parameters and omit non-significant ones. The results indicated that relative scour depth is most affected by the reflection coefficient and water depth at the toe, while the influence of sediment grain size is negligible.
First – order orthotropic shear deformation equations
for the nonlinear elastic bending response of rectangular
plates are introduced. Their solution using a computer
program based on finite differences implementation of the
Dynamic Relaxation (DR) method is outlined. The
convergence and accuracy of the DR solutions for elastic
large deflection response of isotropic, orthotropic, and
laminated plates are established by comparison with various
exact and approximate solutions. The present Dynamic
Relaxation method (DR) coupled with finite differences
method shows a fairly good agreement with other analytical
and numerical methods used in the verification scheme.
It was found that: The convergence and accuracy of the
DR solution is dependent on several factors including
boundary conditions, mesh size and type, fictitious densities,
damping coefficients, time increment and applied load. Also,
the DR large deflection program using uniform finite
differences meshes can be employed in the analysis of
different thicknesses for isotropic, orthotropic or laminated
plates under uniform loads. All the comparison results for
simply supported (SS5) edge conditions showed that
deflection is almost dependent on the direction of the applied
load or the arrangement of the layers
This document summarizes an investigation into using computational fluid dynamics (CFD) to model flow phenomena around a streamlined body. Various analytical, computational, and experimental techniques were used and compared. CFD proved effective at correlating drag values and separation regions with analytical and experimental results, though some turbulence models had major flaws. Different turbulence models in CFD were evaluated to determine which provided the most accurate results compared to theoretical and experimental studies. This helped identify the strengths and weaknesses of different modeling techniques.
This computational fluid dynamics study used simulations to analyze the effect of bend radius on erosion magnitude and location in an S-bend pipe carrying gas-solid or liquid-solid flows. Simulations were run for air velocities of 15.24-45.72 m/s and water velocities of 0.1-10 m/s, with particle sizes of 50-300 microns and bend radius to pipe diameter ratios (r/D) of 1.5, 2.5, and 3.5. Maximum erosion was found at certain velocity-particle size combinations and occurred at specific angle locations within each bend. The simulations aim to provide insight on erosion behavior to inform pipe design and operating conditions.
Fluid dynamics, actually is the study of fluid under motion, governed with a certain set of conservation equations, wherein things are conserved, with reference to mass, momentum & energy.
If these three quantities i.e. mass, momentum & energy are solved entirely we can define any fluid flow. The conservation laws are formulated in the form of equations which we try to solve and that’s what simulation is all about. For my blogs kindly visit: https://www.learncax.com/knowledge-base/blog/by-author/ganesh-visavale
This document summarizes a study that used computational fluid dynamics (CFD) to model soil erosion during a hole erosion test (HET). The study used the k-epsilon turbulence model in ANSYS Fluent to simulate the turbulent flow within the HET apparatus and calculate wall shear stresses. Higher velocities were found to increase erosion rates according to an erosion law relating erosion rate to shear stress exceeding a critical value. Non-uniform erosion along the hole was predicted, unlike one-dimensional models. Results provide insight into how flow variables like velocity affect internal erosion processes.
Numerical study of disk drive rotating flow structure in the cavityeSAT Journals
Abstract
This paper aim in conducting the numerical simulation of laminar flow to explore disk-driven vortical flow structure of a cubical
container subjected to a disk rotation on the roof of the container in different Reynolds numbers to observe the flow structure and
the reason of vortical flow form. For this study, finite difference method with dispersion-relation- preserving (DRP) scheme is
dispersed governing equations space term, but adopt time term with TVD Runge-Kutta method. To add accuracy of numerical,
this thesis also uses topology theory to analyze the characteristic of singular point. Three-dimensional vertical flow is observed
flow structure and move to condition. The result to obtain Reynolds numbers to increase attracting spiral nodes increasingly
approaches the floor of the cavity. We have also depicted the vertical flow structure in terms of cortex cores which provide more
details about how change of the Reynolds number
Keywords: disk-driven, finite difference method, dispersion-relation-preserving (DRP), Runge-Kutta, topology theory
(Fluid Mechanics and Its Applications 57) Victor Ya. Shkadov, Gregory M. Siso...DavidN26
(Fluid Mechanics and Its Applications 57) Victor Ya. Shkadov, Gregory M. Sisoev (auth.), H.-C. Chang (eds.) - IUTAM Symposium on Nonlinear Waves in Multi-Phase Flow_ Proceedings of the IUTAM Symposium.pdf
This document discusses using genetic programming to determine the most effective parameters that influence scour depth at seawalls. Previous studies have developed equations to predict scour depth but they considered a limited number of parameters and had uncertainties. The genetic programming approach was able to evolve models that identify the most significant parameters and omit non-significant ones. The results indicated that relative scour depth is most affected by the reflection coefficient and water depth at the toe, while the influence of sediment grain size is negligible.
First – order orthotropic shear deformation equations
for the nonlinear elastic bending response of rectangular
plates are introduced. Their solution using a computer
program based on finite differences implementation of the
Dynamic Relaxation (DR) method is outlined. The
convergence and accuracy of the DR solutions for elastic
large deflection response of isotropic, orthotropic, and
laminated plates are established by comparison with various
exact and approximate solutions. The present Dynamic
Relaxation method (DR) coupled with finite differences
method shows a fairly good agreement with other analytical
and numerical methods used in the verification scheme.
It was found that: The convergence and accuracy of the
DR solution is dependent on several factors including
boundary conditions, mesh size and type, fictitious densities,
damping coefficients, time increment and applied load. Also,
the DR large deflection program using uniform finite
differences meshes can be employed in the analysis of
different thicknesses for isotropic, orthotropic or laminated
plates under uniform loads. All the comparison results for
simply supported (SS5) edge conditions showed that
deflection is almost dependent on the direction of the applied
load or the arrangement of the layers
This document summarizes an investigation into using computational fluid dynamics (CFD) to model flow phenomena around a streamlined body. Various analytical, computational, and experimental techniques were used and compared. CFD proved effective at correlating drag values and separation regions with analytical and experimental results, though some turbulence models had major flaws. Different turbulence models in CFD were evaluated to determine which provided the most accurate results compared to theoretical and experimental studies. This helped identify the strengths and weaknesses of different modeling techniques.
This computational fluid dynamics study used simulations to analyze the effect of bend radius on erosion magnitude and location in an S-bend pipe carrying gas-solid or liquid-solid flows. Simulations were run for air velocities of 15.24-45.72 m/s and water velocities of 0.1-10 m/s, with particle sizes of 50-300 microns and bend radius to pipe diameter ratios (r/D) of 1.5, 2.5, and 3.5. Maximum erosion was found at certain velocity-particle size combinations and occurred at specific angle locations within each bend. The simulations aim to provide insight on erosion behavior to inform pipe design and operating conditions.
Fluid dynamics, actually is the study of fluid under motion, governed with a certain set of conservation equations, wherein things are conserved, with reference to mass, momentum & energy.
If these three quantities i.e. mass, momentum & energy are solved entirely we can define any fluid flow. The conservation laws are formulated in the form of equations which we try to solve and that’s what simulation is all about. For my blogs kindly visit: https://www.learncax.com/knowledge-base/blog/by-author/ganesh-visavale
This document summarizes a study that used computational fluid dynamics (CFD) to model soil erosion during a hole erosion test (HET). The study used the k-epsilon turbulence model in ANSYS Fluent to simulate the turbulent flow within the HET apparatus and calculate wall shear stresses. Higher velocities were found to increase erosion rates according to an erosion law relating erosion rate to shear stress exceeding a critical value. Non-uniform erosion along the hole was predicted, unlike one-dimensional models. Results provide insight into how flow variables like velocity affect internal erosion processes.
Numerical study of disk drive rotating flow structure in the cavityeSAT Journals
Abstract
This paper aim in conducting the numerical simulation of laminar flow to explore disk-driven vortical flow structure of a cubical
container subjected to a disk rotation on the roof of the container in different Reynolds numbers to observe the flow structure and
the reason of vortical flow form. For this study, finite difference method with dispersion-relation- preserving (DRP) scheme is
dispersed governing equations space term, but adopt time term with TVD Runge-Kutta method. To add accuracy of numerical,
this thesis also uses topology theory to analyze the characteristic of singular point. Three-dimensional vertical flow is observed
flow structure and move to condition. The result to obtain Reynolds numbers to increase attracting spiral nodes increasingly
approaches the floor of the cavity. We have also depicted the vertical flow structure in terms of cortex cores which provide more
details about how change of the Reynolds number
Keywords: disk-driven, finite difference method, dispersion-relation-preserving (DRP), Runge-Kutta, topology theory
This thesis investigates methods for reducing a wave climate dataset into a smaller set of representative wave conditions, while minimizing the prediction error when using the reduced dataset as input for process-based morphodynamic simulations of a coastal beach. Eight different wave climate reduction algorithms are evaluated and compared using bulk sediment transport formulas and the process-based model Delft3D. The research aims to reduce the full wave climate dataset for the energetic coast of Durban, South Africa to 10 representative wave conditions. The key conclusions are that reducing the wave climate introduces significant prediction error, reproducing alongshore sediment transport is most successful but cross-shore transport and coastal morphology are more challenging to capture accurately, and doubling the number of representative conditions to 20 does not
Solid particle erosion sand monitoring and transport and erosion corrosion ...Shokrollah Hassani
This document summarizes a two-day short course on solid particle erosion, sand monitoring and transport, and erosion-corrosion in oil and gas production taught by Dr. Siamack Shirazi. The course is aimed at managers, operators, researchers, and engineers involved in production equipment. Attendees will learn how to predict and manage erosion using modeling software, monitor sand production, and understand CO2 corrosion and erosion-corrosion scenarios. The course will cover multiphase flow fundamentals, erosion mechanisms, prediction models, sand management, CO2 corrosion modeling, and erosion-corrosion case studies.
Offshore structures are continuously exposed to extremely varying aerodynamic
and hydrodynamic loads. The storm waves and breaking waves may cause significant
impact on coastal and offshore structures such as vertical sea wall, wind turbines,
LNG carriers and submarine pipelines etc. The prediction of the breaking wave
impact pressure is the important aspect in the design of those structures. The breaking
wave forces produce the highest hydrodynamic loads on substructures in shallow
water, predominantly plunging breaking waves. Owing to the complex and transient
nature of the impact forces it requires more details concerning the physics of breaking
waves and nature of wave interaction with those structures.
In this paper, A Piston-type wave generator was incorporated in the
computational domain to generate waves. Flow 3D was used for simulating 3D
numerical wave tank. The desired breaking waves are simulated using the concept of
wave focusing using Flow 3D solver. These waves are made to impinge on the elastic
circular cylinders of different materials such as PVC, timber and concrete by varying
the support conditions such as cantilever, both ends fixed, inclined support with 30º
inclination. The hydrodynamic response and the structural response are analysed and
validated with the experimental literatures. The maximum impact pressure transpired
on the cylinder due to plunging wave impact from numerical simulation is found to be
eight times of the non-breaking waves
Hybrid turbulence models aim to unite the strengths of RANS and LES approaches. Recent developments include improved definitions of the hybrid length scale to better handle wall-bounded and massively separated flows. Further research focuses on more adaptable and aggressive formulations to generate faster transition from modeled to resolved turbulence. While hybrid models have been applied successfully in various cases, more comprehensive testing on diverse test cases is still needed to fully evaluate model performance and development.
● Comparison of Potential Theory and Morison Equation for Deformable Horizontal Cylinders
● Structural Integrity Analysis of Containers Lost at Sea Using Finite Element Method
● Dynamic Analysis of Splash-zone Crossing Operation for a Subsea Template
● Current Status and Future Trends for Mooring Systems of Floating Offshore Wind Turbines
● Marine Structures under Special Loads
This document summarizes a study that used computational fluid dynamics (CFD) to model soil erosion during a hole erosion test (HET). The study used the k-epsilon turbulence model in Fluent software to simulate the biphasic turbulent flow and resulting shear stresses at the water-soil interface. This allowed for a three-dimensional analysis of erosion rates along the hole, unlike typical one-dimensional models. Results showed the inlet side of the hole experienced more erosion than the outlet side due to non-uniform shear stresses. The model aims to better understand and predict piping failures in hydraulic structures by quantifying the effects of flow velocity on erosion rates.
This document is a thesis submitted by Michael Frind to the University of Waterloo in fulfillment of a Master of Science degree in hydrogeology. The thesis examines issues related to advective-dispersive transport modeling, specifically numerical dispersion and formulations of the dispersion tensor. To investigate these issues, Frind conducts modeling studies using an aquifer-scale box model under saturated conditions. The results show that with appropriate discretization, numerical dispersion can be minimized. The modeling also finds little difference between two formulations of the dispersion tensor under the conditions examined, but notes the potential benefit of an alternative formulation for variably saturated systems.
Experimental flow visualization for flow around multiple side-by-side circula...Santosh Sivaramakrishnan
The document summarizes an experimental study of flow visualization around four side-by-side circular cylinders at a Reynolds number of 190 and spacing-to-diameter ratios from 1.0 to 6.0. The study found that at low spacing, the flow regime was chaotic, while at high spacing above 4.0, the vortex shedding was synchronous. Between spacing ratios of 1.0 to 3.0, the flow transitioned through a quasi-periodic regime as the shed vortices interacted at increasing distances from the cylinders with increasing spacing. The results provide benchmark data for numerical simulations of flow around multiple circular cylinders.
This document discusses the validation of RotCFD, a new software for rotorcraft design. RotCFD uses computational fluid dynamics (CFD) simulations but its results must be validated to verify the software's accuracy. The document proposes comparing RotCFD's computational results for the downwash and outwash of aircraft like the CH-53, CH-47 Chinook, UH-60 BlackHawk, and V-22 Osprey against existing experimental data for these aircraft. The CAD models of the aircraft were created in CreoParametric and will be analyzed in RotCFD using its momentum source approach to simulate rotor effects.
This thesis investigates the use of computational fluid dynamics (CFD) to predict wind loads on heliostats. The student uses several turbulence models in ANSYS Fluent to simulate flow over a flat plate and heliostat, including the RNG k-ε, realizable k-ε, and SST k-ω models. For steady flow, the realizable k-ε model best predicts drag on the flat plate. For transient heliostat simulations, SST k-ω is most suitable. While CFD shows promise, the conclusions are that more advanced modeling like LES is needed to accurately predict wind loads for heliostat design.
[Harry edmar]hydrodynamics concepts and experimentsEnrique Buenaonda
This chapter develops a coupled fluid-structure model to simulate the interaction between water flow and a flexible fishing net. The model combines a porous media fluid model and a lumped-mass mechanical model. The porous media fluid model uses the Navier-Stokes equations to simulate flow around a rigid net, while the lumped-mass model simulates net deformation. An iterative scheme is used to solve for the steady fluid-net interaction. The model aims to better understand hydrodynamic forces on nets and flow patterns, which has significance for net cage and aquaculture design.
This paper analyzes wall shear stress and static pressure distributions around a competitive swimmer using computational fluid dynamics (CFD). Three head positions - lifted up, aligned, and lowered - and three velocities (1.4 m/s, 2.2 m/s, and 3.1 m/s) corresponding to different competitive levels are studied. The Reynolds-averaged Navier-Stokes equations are solved using the standard k-ω turbulence model in ANSYS Fluent. Results show that wall shear stress and resulting drag force increase with velocity. High wall shear stresses are observed where the body presents complex surface geometries like the head, shoulders, buttocks, heel, and chest. The head position is found to influence
Webinar presentation ocean modelling and early-warning system for the gulf ...Deltares
The document describes the development and implementation of an early warning system for coastal flooding along the coast of Thailand. It uses the Delft-FEWS software platform along with hydrodynamic modeling with Delft3D Flexible Mesh and wave modeling with SWAN to generate 3-day forecasts of tide, storm surge, and waves. The system was developed jointly by Deltares and the Hydro and Agro Informatics Institute in Thailand and is now fully operational, providing daily coastal flood forecasts.
This document discusses estimation of flotation rate constants and particle-bubble interactions considering key hydrodynamic parameters. It summarizes two stages of the study:
1) Prediction and evaluation of particle-bubble sub-processes using analytical and numerical models, finding numerical models predict higher collection efficiencies due to modeling assumptions.
2) Using response surface modeling to determine the relative intensity and interrelations of key factors (particle size, density, bubble size, velocity, turbulence) on particle-bubble encounter efficiency and flotation rate constant, finding particle size most affects encounter efficiency while bubble velocity most affects rate constant.
The study aims to overcome limitations in modeling particle-bubble interactions and kinetics, and provides new insights into inconsist
An Algebraic Multigrid Solver For Transonic Flow ProblemsLisa Muthukumar
This document summarizes an article about developing an algebraic multigrid solver for transonic flow problems. The key points are:
- The solver is based on the full potential equation, which can model subsonic, transonic, and supersonic flows.
- Algebraic multigrid methods are used instead of geometric multigrid to avoid dependencies on grid geometry.
- The discretization approach handles the mixed elliptic-hyperbolic nature of the governing equations across flow regimes.
- Applications to complex geometries on structured grids are demonstrated, achieving an order of magnitude reduction in residual per cycle.
In this paper, the unsteady motion of a spherical particle rolling down an inclined tube in a
Newtonian fluid for a range of Reynolds numbers was solved using a simulation method called
the Differential Transformation Method (DTM). The concept of differential transformation is
briefly introduced, and then we employed it to derive solution of nonlinear equation. The
obtained results for displacement, velocity and acceleration of the motion from DTM are
compared with those from numerical solution to verify the accuracy of the proposed method.
The effects of particle diameter (size), continues phase viscosity and inclination angles was
studied. As an important result it was found that the inclination angle does not affect the
acceleration duration. The results reveal that the Differential Transformation Method can achieve suitable results in predicting the solution of such problems.
This document discusses recent trends in computational fluid dynamics (CFD). It begins by defining CFD as using numerical analysis and algorithms to solve fluid flow problems described by partial differential equations. CFD offers advantages over physical experiments by enabling low-cost simulation-based design and analysis of fluid phenomena that are difficult to measure experimentally. The document outlines the basic CFD process of geometry description, model selection, grid generation, solution, and post-processing. It provides examples of CFD applications in aerospace, automotive, biomedical, and other industrial fields to analyze designs. The conclusion discusses iterative solution methods and potential future advances in multidisciplinary and on-demand CFD simulations.
The document provides an overview of principles of seismic data interpretation. It discusses fundamentals of seismic acquisition and processing such as seismic response, phase, polarity, reflections, and resolution. It also covers topics like structural interpretation pitfalls, seismic interpretation workflows involving building databases and time-depth relationships, and structural styles. The document includes sections on depth conversion, subsurface mapping techniques, and different types of velocities.
Pergamon Transpn. Res.-B. Vol. 28B, No. 4, pp. 269-287, 19.docxkarlhennesey
Pergamon
Transpn. Res.-B. Vol. 28B, No. 4, pp. 269-287, 1994
Copyright 0 1994 Elsevier Science Ltd
Printed in the UK. All rights reserved
0191-2615194 $6.00 + .OO
0191-2615(93)E0002-3
THE CELL TRANSMISSION MODEL: A DYNAMIC
REPRESENTATION OF HIGHWAY TRAFFIC
CONSISTENT WITH THE HYDRODYNAMIC THEORY
CARLOS F. DAGANZO
Department of Civil Engineering and Institute of Transportation Studies,
University of California, Berkeley CA 94720, U.S.A.
(Received 23 October 1992; in revisedform 13 July 1993)
Abstract-This paper presents a simple representation of traffic on a highway with a single
entrance and exit. The representation can be used to predict traffic’s evolution over time and
space, including transient phenomena such as the building, propagation, and dissipation of
queues. The easy-to-solve difference equations used to predict traffic’s evolution are shown to be
the discrete analog of the differential equations arising from a special case of the hydrodynamic
model of traffic flow. The proposed method automatically generates appropriate changes in
density at locations where the hydrodynamic theory would call for a shockwave; i.e., a jump in
density such as those typically seen at the end of every queue. The complex side calculations
required by classical methods to keep track of shockwaves are thus eliminated. The paper also
shows how the equations can mimic the real-life development of stop-and-go traffic within moving
queues.
1. INTRODUCTION
Accurate descriptions of highway traffic flow over transportation networks, whether at
the planning or operations level, must recognize that the vehicles traveling on any section
of the network must be bound for specific destinations.
Static traffic assignment models used for transportation planning (see Sheffi, 1985,
for example) achieve this goal by describing the flow on a link of the network by its
components by final destination; e.g., by specifying a variable yid that represents the
amount of flow on link i that is ultimately bound for destination d. Unfortunately, this is
much more difficult to do for dynamic network flow problems (with time-dependent
origin-destination (O-D) flows) because the functional dependence of the link flows at
time t, yid(f), on the collection of all past flows is quite complex. This problem manifests
itself both at the planning level, where networks are quite complex, and at the operations
level, where networks are simpler, but more detail is sought about the system’s evolution.
Although dynamic traffic assignment models -planning level models involving large
networks- typically recognize that traffic travels to many destinations, the models are
based on simplistic flow relationships that are not perfectly consistent with the conserva-
tion laws of traffic. A planned sequel to this paper will discuss this in more detail.
Traffic operations models can be microscopic or macroscopic. Microscopic simula-
tions (e.g., Schw ...
The Hydrodynamic Performance Examination of a New Floating Breakwater Configu...IJAEMSJORNAL
It is critical to protect coastal and offshore structures. Most current studies and scientific investigations are centered on how to protect seashore with an efficient and cost-effective system. This study involved the testing of a new floating breakwater configuration (FB). A series of experiments were carried out in the lab of The Higher Institute of Engineering (El-shorouk City) on the new model and the traditional vertical plane FB without a curved face to compare their behaviours and performance in wave attenuation. The incident, reflected, and transmitted wave heights were measured, and the coefficients of reflection, transmission, and energy dissipation were calculated using these measurements. In terms of hydrodynamic performance, the curved-face floating breakwater outperformed the traditional vertical floating breakwater, according to the study's highlights. The curved face model significantly reduced wave transmission values when compared to the traditional vertical configuration. The greater the concavity of the curve, the better the model handles waves, especially when the wave steepness is low.
Optimizing Post Remediation Groundwater Performance with Enhanced Microbiolog...Joshua Orris
Results of geophysics and pneumatic injection pilot tests during 2003 – 2007 yielded significant positive results for injection delivery design and contaminant mass treatment, resulting in permanent shut-down of an existing groundwater Pump & Treat system.
Accessible source areas were subsequently removed (2011) by soil excavation and treated with the placement of Emulsified Vegetable Oil EVO and zero-valent iron ZVI to accelerate treatment of impacted groundwater in overburden and weathered fractured bedrock. Post pilot test and post remediation groundwater monitoring has included analyses of CVOCs, organic fatty acids, dissolved gases and QuantArray® -Chlor to quantify key microorganisms (e.g., Dehalococcoides, Dehalobacter, etc.) and functional genes (e.g., vinyl chloride reductase, methane monooxygenase, etc.) to assess potential for reductive dechlorination and aerobic cometabolism of CVOCs.
In 2022, the first commercial application of MetaArray™ was performed at the site. MetaArray™ utilizes statistical analysis, such as principal component analysis and multivariate analysis to provide evidence that reductive dechlorination is active or even that it is slowing. This creates actionable data allowing users to save money by making important site management decisions earlier.
The results of the MetaArray™ analysis’ support vector machine (SVM) identified groundwater monitoring wells with a 80% confidence that were characterized as either Limited for Reductive Decholorination or had a High Reductive Reduction Dechlorination potential. The results of MetaArray™ will be used to further optimize the site’s post remediation monitoring program for monitored natural attenuation.
This thesis investigates methods for reducing a wave climate dataset into a smaller set of representative wave conditions, while minimizing the prediction error when using the reduced dataset as input for process-based morphodynamic simulations of a coastal beach. Eight different wave climate reduction algorithms are evaluated and compared using bulk sediment transport formulas and the process-based model Delft3D. The research aims to reduce the full wave climate dataset for the energetic coast of Durban, South Africa to 10 representative wave conditions. The key conclusions are that reducing the wave climate introduces significant prediction error, reproducing alongshore sediment transport is most successful but cross-shore transport and coastal morphology are more challenging to capture accurately, and doubling the number of representative conditions to 20 does not
Solid particle erosion sand monitoring and transport and erosion corrosion ...Shokrollah Hassani
This document summarizes a two-day short course on solid particle erosion, sand monitoring and transport, and erosion-corrosion in oil and gas production taught by Dr. Siamack Shirazi. The course is aimed at managers, operators, researchers, and engineers involved in production equipment. Attendees will learn how to predict and manage erosion using modeling software, monitor sand production, and understand CO2 corrosion and erosion-corrosion scenarios. The course will cover multiphase flow fundamentals, erosion mechanisms, prediction models, sand management, CO2 corrosion modeling, and erosion-corrosion case studies.
Offshore structures are continuously exposed to extremely varying aerodynamic
and hydrodynamic loads. The storm waves and breaking waves may cause significant
impact on coastal and offshore structures such as vertical sea wall, wind turbines,
LNG carriers and submarine pipelines etc. The prediction of the breaking wave
impact pressure is the important aspect in the design of those structures. The breaking
wave forces produce the highest hydrodynamic loads on substructures in shallow
water, predominantly plunging breaking waves. Owing to the complex and transient
nature of the impact forces it requires more details concerning the physics of breaking
waves and nature of wave interaction with those structures.
In this paper, A Piston-type wave generator was incorporated in the
computational domain to generate waves. Flow 3D was used for simulating 3D
numerical wave tank. The desired breaking waves are simulated using the concept of
wave focusing using Flow 3D solver. These waves are made to impinge on the elastic
circular cylinders of different materials such as PVC, timber and concrete by varying
the support conditions such as cantilever, both ends fixed, inclined support with 30º
inclination. The hydrodynamic response and the structural response are analysed and
validated with the experimental literatures. The maximum impact pressure transpired
on the cylinder due to plunging wave impact from numerical simulation is found to be
eight times of the non-breaking waves
Hybrid turbulence models aim to unite the strengths of RANS and LES approaches. Recent developments include improved definitions of the hybrid length scale to better handle wall-bounded and massively separated flows. Further research focuses on more adaptable and aggressive formulations to generate faster transition from modeled to resolved turbulence. While hybrid models have been applied successfully in various cases, more comprehensive testing on diverse test cases is still needed to fully evaluate model performance and development.
● Comparison of Potential Theory and Morison Equation for Deformable Horizontal Cylinders
● Structural Integrity Analysis of Containers Lost at Sea Using Finite Element Method
● Dynamic Analysis of Splash-zone Crossing Operation for a Subsea Template
● Current Status and Future Trends for Mooring Systems of Floating Offshore Wind Turbines
● Marine Structures under Special Loads
This document summarizes a study that used computational fluid dynamics (CFD) to model soil erosion during a hole erosion test (HET). The study used the k-epsilon turbulence model in Fluent software to simulate the biphasic turbulent flow and resulting shear stresses at the water-soil interface. This allowed for a three-dimensional analysis of erosion rates along the hole, unlike typical one-dimensional models. Results showed the inlet side of the hole experienced more erosion than the outlet side due to non-uniform shear stresses. The model aims to better understand and predict piping failures in hydraulic structures by quantifying the effects of flow velocity on erosion rates.
This document is a thesis submitted by Michael Frind to the University of Waterloo in fulfillment of a Master of Science degree in hydrogeology. The thesis examines issues related to advective-dispersive transport modeling, specifically numerical dispersion and formulations of the dispersion tensor. To investigate these issues, Frind conducts modeling studies using an aquifer-scale box model under saturated conditions. The results show that with appropriate discretization, numerical dispersion can be minimized. The modeling also finds little difference between two formulations of the dispersion tensor under the conditions examined, but notes the potential benefit of an alternative formulation for variably saturated systems.
Experimental flow visualization for flow around multiple side-by-side circula...Santosh Sivaramakrishnan
The document summarizes an experimental study of flow visualization around four side-by-side circular cylinders at a Reynolds number of 190 and spacing-to-diameter ratios from 1.0 to 6.0. The study found that at low spacing, the flow regime was chaotic, while at high spacing above 4.0, the vortex shedding was synchronous. Between spacing ratios of 1.0 to 3.0, the flow transitioned through a quasi-periodic regime as the shed vortices interacted at increasing distances from the cylinders with increasing spacing. The results provide benchmark data for numerical simulations of flow around multiple circular cylinders.
This document discusses the validation of RotCFD, a new software for rotorcraft design. RotCFD uses computational fluid dynamics (CFD) simulations but its results must be validated to verify the software's accuracy. The document proposes comparing RotCFD's computational results for the downwash and outwash of aircraft like the CH-53, CH-47 Chinook, UH-60 BlackHawk, and V-22 Osprey against existing experimental data for these aircraft. The CAD models of the aircraft were created in CreoParametric and will be analyzed in RotCFD using its momentum source approach to simulate rotor effects.
This thesis investigates the use of computational fluid dynamics (CFD) to predict wind loads on heliostats. The student uses several turbulence models in ANSYS Fluent to simulate flow over a flat plate and heliostat, including the RNG k-ε, realizable k-ε, and SST k-ω models. For steady flow, the realizable k-ε model best predicts drag on the flat plate. For transient heliostat simulations, SST k-ω is most suitable. While CFD shows promise, the conclusions are that more advanced modeling like LES is needed to accurately predict wind loads for heliostat design.
[Harry edmar]hydrodynamics concepts and experimentsEnrique Buenaonda
This chapter develops a coupled fluid-structure model to simulate the interaction between water flow and a flexible fishing net. The model combines a porous media fluid model and a lumped-mass mechanical model. The porous media fluid model uses the Navier-Stokes equations to simulate flow around a rigid net, while the lumped-mass model simulates net deformation. An iterative scheme is used to solve for the steady fluid-net interaction. The model aims to better understand hydrodynamic forces on nets and flow patterns, which has significance for net cage and aquaculture design.
This paper analyzes wall shear stress and static pressure distributions around a competitive swimmer using computational fluid dynamics (CFD). Three head positions - lifted up, aligned, and lowered - and three velocities (1.4 m/s, 2.2 m/s, and 3.1 m/s) corresponding to different competitive levels are studied. The Reynolds-averaged Navier-Stokes equations are solved using the standard k-ω turbulence model in ANSYS Fluent. Results show that wall shear stress and resulting drag force increase with velocity. High wall shear stresses are observed where the body presents complex surface geometries like the head, shoulders, buttocks, heel, and chest. The head position is found to influence
Webinar presentation ocean modelling and early-warning system for the gulf ...Deltares
The document describes the development and implementation of an early warning system for coastal flooding along the coast of Thailand. It uses the Delft-FEWS software platform along with hydrodynamic modeling with Delft3D Flexible Mesh and wave modeling with SWAN to generate 3-day forecasts of tide, storm surge, and waves. The system was developed jointly by Deltares and the Hydro and Agro Informatics Institute in Thailand and is now fully operational, providing daily coastal flood forecasts.
This document discusses estimation of flotation rate constants and particle-bubble interactions considering key hydrodynamic parameters. It summarizes two stages of the study:
1) Prediction and evaluation of particle-bubble sub-processes using analytical and numerical models, finding numerical models predict higher collection efficiencies due to modeling assumptions.
2) Using response surface modeling to determine the relative intensity and interrelations of key factors (particle size, density, bubble size, velocity, turbulence) on particle-bubble encounter efficiency and flotation rate constant, finding particle size most affects encounter efficiency while bubble velocity most affects rate constant.
The study aims to overcome limitations in modeling particle-bubble interactions and kinetics, and provides new insights into inconsist
An Algebraic Multigrid Solver For Transonic Flow ProblemsLisa Muthukumar
This document summarizes an article about developing an algebraic multigrid solver for transonic flow problems. The key points are:
- The solver is based on the full potential equation, which can model subsonic, transonic, and supersonic flows.
- Algebraic multigrid methods are used instead of geometric multigrid to avoid dependencies on grid geometry.
- The discretization approach handles the mixed elliptic-hyperbolic nature of the governing equations across flow regimes.
- Applications to complex geometries on structured grids are demonstrated, achieving an order of magnitude reduction in residual per cycle.
In this paper, the unsteady motion of a spherical particle rolling down an inclined tube in a
Newtonian fluid for a range of Reynolds numbers was solved using a simulation method called
the Differential Transformation Method (DTM). The concept of differential transformation is
briefly introduced, and then we employed it to derive solution of nonlinear equation. The
obtained results for displacement, velocity and acceleration of the motion from DTM are
compared with those from numerical solution to verify the accuracy of the proposed method.
The effects of particle diameter (size), continues phase viscosity and inclination angles was
studied. As an important result it was found that the inclination angle does not affect the
acceleration duration. The results reveal that the Differential Transformation Method can achieve suitable results in predicting the solution of such problems.
This document discusses recent trends in computational fluid dynamics (CFD). It begins by defining CFD as using numerical analysis and algorithms to solve fluid flow problems described by partial differential equations. CFD offers advantages over physical experiments by enabling low-cost simulation-based design and analysis of fluid phenomena that are difficult to measure experimentally. The document outlines the basic CFD process of geometry description, model selection, grid generation, solution, and post-processing. It provides examples of CFD applications in aerospace, automotive, biomedical, and other industrial fields to analyze designs. The conclusion discusses iterative solution methods and potential future advances in multidisciplinary and on-demand CFD simulations.
The document provides an overview of principles of seismic data interpretation. It discusses fundamentals of seismic acquisition and processing such as seismic response, phase, polarity, reflections, and resolution. It also covers topics like structural interpretation pitfalls, seismic interpretation workflows involving building databases and time-depth relationships, and structural styles. The document includes sections on depth conversion, subsurface mapping techniques, and different types of velocities.
Pergamon Transpn. Res.-B. Vol. 28B, No. 4, pp. 269-287, 19.docxkarlhennesey
Pergamon
Transpn. Res.-B. Vol. 28B, No. 4, pp. 269-287, 1994
Copyright 0 1994 Elsevier Science Ltd
Printed in the UK. All rights reserved
0191-2615194 $6.00 + .OO
0191-2615(93)E0002-3
THE CELL TRANSMISSION MODEL: A DYNAMIC
REPRESENTATION OF HIGHWAY TRAFFIC
CONSISTENT WITH THE HYDRODYNAMIC THEORY
CARLOS F. DAGANZO
Department of Civil Engineering and Institute of Transportation Studies,
University of California, Berkeley CA 94720, U.S.A.
(Received 23 October 1992; in revisedform 13 July 1993)
Abstract-This paper presents a simple representation of traffic on a highway with a single
entrance and exit. The representation can be used to predict traffic’s evolution over time and
space, including transient phenomena such as the building, propagation, and dissipation of
queues. The easy-to-solve difference equations used to predict traffic’s evolution are shown to be
the discrete analog of the differential equations arising from a special case of the hydrodynamic
model of traffic flow. The proposed method automatically generates appropriate changes in
density at locations where the hydrodynamic theory would call for a shockwave; i.e., a jump in
density such as those typically seen at the end of every queue. The complex side calculations
required by classical methods to keep track of shockwaves are thus eliminated. The paper also
shows how the equations can mimic the real-life development of stop-and-go traffic within moving
queues.
1. INTRODUCTION
Accurate descriptions of highway traffic flow over transportation networks, whether at
the planning or operations level, must recognize that the vehicles traveling on any section
of the network must be bound for specific destinations.
Static traffic assignment models used for transportation planning (see Sheffi, 1985,
for example) achieve this goal by describing the flow on a link of the network by its
components by final destination; e.g., by specifying a variable yid that represents the
amount of flow on link i that is ultimately bound for destination d. Unfortunately, this is
much more difficult to do for dynamic network flow problems (with time-dependent
origin-destination (O-D) flows) because the functional dependence of the link flows at
time t, yid(f), on the collection of all past flows is quite complex. This problem manifests
itself both at the planning level, where networks are quite complex, and at the operations
level, where networks are simpler, but more detail is sought about the system’s evolution.
Although dynamic traffic assignment models -planning level models involving large
networks- typically recognize that traffic travels to many destinations, the models are
based on simplistic flow relationships that are not perfectly consistent with the conserva-
tion laws of traffic. A planned sequel to this paper will discuss this in more detail.
Traffic operations models can be microscopic or macroscopic. Microscopic simula-
tions (e.g., Schw ...
The Hydrodynamic Performance Examination of a New Floating Breakwater Configu...IJAEMSJORNAL
It is critical to protect coastal and offshore structures. Most current studies and scientific investigations are centered on how to protect seashore with an efficient and cost-effective system. This study involved the testing of a new floating breakwater configuration (FB). A series of experiments were carried out in the lab of The Higher Institute of Engineering (El-shorouk City) on the new model and the traditional vertical plane FB without a curved face to compare their behaviours and performance in wave attenuation. The incident, reflected, and transmitted wave heights were measured, and the coefficients of reflection, transmission, and energy dissipation were calculated using these measurements. In terms of hydrodynamic performance, the curved-face floating breakwater outperformed the traditional vertical floating breakwater, according to the study's highlights. The curved face model significantly reduced wave transmission values when compared to the traditional vertical configuration. The greater the concavity of the curve, the better the model handles waves, especially when the wave steepness is low.
Optimizing Post Remediation Groundwater Performance with Enhanced Microbiolog...Joshua Orris
Results of geophysics and pneumatic injection pilot tests during 2003 – 2007 yielded significant positive results for injection delivery design and contaminant mass treatment, resulting in permanent shut-down of an existing groundwater Pump & Treat system.
Accessible source areas were subsequently removed (2011) by soil excavation and treated with the placement of Emulsified Vegetable Oil EVO and zero-valent iron ZVI to accelerate treatment of impacted groundwater in overburden and weathered fractured bedrock. Post pilot test and post remediation groundwater monitoring has included analyses of CVOCs, organic fatty acids, dissolved gases and QuantArray® -Chlor to quantify key microorganisms (e.g., Dehalococcoides, Dehalobacter, etc.) and functional genes (e.g., vinyl chloride reductase, methane monooxygenase, etc.) to assess potential for reductive dechlorination and aerobic cometabolism of CVOCs.
In 2022, the first commercial application of MetaArray™ was performed at the site. MetaArray™ utilizes statistical analysis, such as principal component analysis and multivariate analysis to provide evidence that reductive dechlorination is active or even that it is slowing. This creates actionable data allowing users to save money by making important site management decisions earlier.
The results of the MetaArray™ analysis’ support vector machine (SVM) identified groundwater monitoring wells with a 80% confidence that were characterized as either Limited for Reductive Decholorination or had a High Reductive Reduction Dechlorination potential. The results of MetaArray™ will be used to further optimize the site’s post remediation monitoring program for monitored natural attenuation.
ENVIRONMENT~ Renewable Energy Sources and their future prospects.tiwarimanvi3129
This presentation is for us to know that how our Environment need Attention for protection of our natural resources which are depleted day by day that's why we need to take time and shift our attention to renewable energy sources instead of non-renewable sources which are better and Eco-friendly for our environment. these renewable energy sources are so helpful for our planet and for every living organism which depends on environment.
Presented by The Global Peatlands Assessment: Mapping, Policy, and Action at GLF Peatlands 2024 - The Global Peatlands Assessment: Mapping, Policy, and Action
Kinetic studies on malachite green dye adsorption from aqueous solutions by A...Open Access Research Paper
Water polluted by dyestuffs compounds is a global threat to health and the environment; accordingly, we prepared a green novel sorbent chemical and Physical system from an algae, chitosan and chitosan nanoparticle and impregnated with algae with chitosan nanocomposite for the sorption of Malachite green dye from water. The algae with chitosan nanocomposite by a simple method and used as a recyclable and effective adsorbent for the removal of malachite green dye from aqueous solutions. Algae, chitosan, chitosan nanoparticle and algae with chitosan nanocomposite were characterized using different physicochemical methods. The functional groups and chemical compounds found in algae, chitosan, chitosan algae, chitosan nanoparticle, and chitosan nanoparticle with algae were identified using FTIR, SEM, and TGADTA/DTG techniques. The optimal adsorption conditions, different dosages, pH and Temperature the amount of algae with chitosan nanocomposite were determined. At optimized conditions and the batch equilibrium studies more than 99% of the dye was removed. The adsorption process data matched well kinetics showed that the reaction order for dye varied with pseudo-first order and pseudo-second order. Furthermore, the maximum adsorption capacity of the algae with chitosan nanocomposite toward malachite green dye reached as high as 15.5mg/g, respectively. Finally, multiple times reusing of algae with chitosan nanocomposite and removing dye from a real wastewater has made it a promising and attractive option for further practical applications.
Evolving Lifecycles with High Resolution Site Characterization (HRSC) and 3-D...Joshua Orris
The incorporation of a 3DCSM and completion of HRSC provided a tool for enhanced, data-driven, decisions to support a change in remediation closure strategies. Currently, an approved pilot study has been obtained to shut-down the remediation systems (ISCO, P&T) and conduct a hydraulic study under non-pumping conditions. A separate micro-biological bench scale treatability study was competed that yielded positive results for an emerging innovative technology. As a result, a field pilot study has commenced with results expected in nine-twelve months. With the results of the hydraulic study, field pilot studies and an updated risk assessment leading site monitoring optimization cost lifecycle savings upwards of $15MM towards an alternatively evolved best available technology remediation closure strategy.
Improving the viability of probiotics by encapsulation methods for developmen...Open Access Research Paper
The popularity of functional foods among scientists and common people has been increasing day by day. Awareness and modernization make the consumer think better regarding food and nutrition. Now a day’s individual knows very well about the relation between food consumption and disease prevalence. Humans have a diversity of microbes in the gut that together form the gut microflora. Probiotics are the health-promoting live microbial cells improve host health through gut and brain connection and fighting against harmful bacteria. Bifidobacterium and Lactobacillus are the two bacterial genera which are considered to be probiotic. These good bacteria are facing challenges of viability. There are so many factors such as sensitivity to heat, pH, acidity, osmotic effect, mechanical shear, chemical components, freezing and storage time as well which affects the viability of probiotics in the dairy food matrix as well as in the gut. Multiple efforts have been done in the past and ongoing in present for these beneficial microbial population stability until their destination in the gut. One of a useful technique known as microencapsulation makes the probiotic effective in the diversified conditions and maintain these microbe’s community to the optimum level for achieving targeted benefits. Dairy products are found to be an ideal vehicle for probiotic incorporation. It has been seen that the encapsulated microbial cells show higher viability than the free cells in different processing and storage conditions as well as against bile salts in the gut. They make the food functional when incorporated, without affecting the product sensory characteristics.
Climate Change All over the World .pptxsairaanwer024
Climate change refers to significant and lasting changes in the average weather patterns over periods ranging from decades to millions of years. It encompasses both global warming driven by human emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. While climate change is a natural phenomenon, human activities, particularly since the Industrial Revolution, have accelerated its pace and intensity
Microbial characterisation and identification, and potability of River Kuywa ...Open Access Research Paper
Water contamination is one of the major causes of water borne diseases worldwide. In Kenya, approximately 43% of people lack access to potable water due to human contamination. River Kuywa water is currently experiencing contamination due to human activities. Its water is widely used for domestic, agricultural, industrial and recreational purposes. This study aimed at characterizing bacteria and fungi in river Kuywa water. Water samples were randomly collected from four sites of the river: site A (Matisi), site B (Ngwelo), site C (Nzoia water pump) and site D (Chalicha), during the dry season (January-March 2018) and wet season (April-July 2018) and were transported to Maseno University Microbiology and plant pathology laboratory for analysis. The characterization and identification of bacteria and fungi were carried out using standard microbiological techniques. Nine bacterial genera and three fungi were identified from Kuywa river water. Clostridium spp., Staphylococcus spp., Enterobacter spp., Streptococcus spp., E. coli, Klebsiella spp., Shigella spp., Proteus spp. and Salmonella spp. Fungi were Fusarium oxysporum, Aspergillus flavus complex and Penicillium species. Wet season recorded highest bacterial and fungal counts (6.61-7.66 and 3.83-6.75cfu/ml) respectively. The results indicated that the river Kuywa water is polluted and therefore unsafe for human consumption before treatment. It is therefore recommended that the communities to ensure that they boil water especially for drinking.