The current study examines the generation and propagation of a Third order solitary water wave along
the channel. Surface displacement and wave profi le prediction challenges are interesting subjects in the
fi eld of marine engineering and many researchers have tried to investigate these parameters. To study the
wave propagation problem, here, fi rstly the meshless Incompressible Smoothed Particle Hydrodynamics
(ISPH) numerical method is described. Secondly,
In this study the kinematic wave equation has been solved numerically using the modified Lax
explicit finite difference scheme (MLEFDS) and used for flood routing in a wide prismatic channel and a nonprismatic
channel. Two flood waves, one sinusoidal wave and one exponential wave, have been imposed at the
upstream boundary of the channel in which the flow is initially uniform. Six different schemes have been
introduced and used to compute the routing parameter, the wave celerity c. Two of these schemes are based on
constant depth and use constant celerity throughout the computation process. The rest of the schemes are based
on local depths and give celerity dependent on time and space. The effects of the routing parameter c on the
travel time of flood wave, the subsidence of the flood peak and the conservation flood flow volume have been
studied. The results seem to indicate that there is a minimal loss/gain of flow volume whatever the scheme is.
While it is confirmed that neither of the schemes is 100% volume conservative, it is found that the scheme
Kinematic Wave Model-2 (KWM-II) gives the most accurate result giving only 0.1% error in perspective of
volume conservation. The results obtained in this study are in good qualitative agreement with those obtained in
other similar studies.
Austin Journal of Hydrology is an open access, peer reviewed, scholarly journal dedicated to publish articles in all areas of Hydrology.
The aim of the journal is to provide a platform for engineers, scientists and academicians all over the world to endorse, discuss and share various new issues and developments in diverse areas of hydrology.
Austin Journal of Hydrology accepts original research articles, review articles, case reports, commentaries, clinical images and rapid communication on all the aspects of Hydrology.
In this study the kinematic wave equation has been solved numerically using the modified Lax
explicit finite difference scheme (MLEFDS) and used for flood routing in a wide prismatic channel and a nonprismatic
channel. Two flood waves, one sinusoidal wave and one exponential wave, have been imposed at the
upstream boundary of the channel in which the flow is initially uniform. Six different schemes have been
introduced and used to compute the routing parameter, the wave celerity c. Two of these schemes are based on
constant depth and use constant celerity throughout the computation process. The rest of the schemes are based
on local depths and give celerity dependent on time and space. The effects of the routing parameter c on the
travel time of flood wave, the subsidence of the flood peak and the conservation flood flow volume have been
studied. The results seem to indicate that there is a minimal loss/gain of flow volume whatever the scheme is.
While it is confirmed that neither of the schemes is 100% volume conservative, it is found that the scheme
Kinematic Wave Model-2 (KWM-II) gives the most accurate result giving only 0.1% error in perspective of
volume conservation. The results obtained in this study are in good qualitative agreement with those obtained in
other similar studies.
Austin Journal of Hydrology is an open access, peer reviewed, scholarly journal dedicated to publish articles in all areas of Hydrology.
The aim of the journal is to provide a platform for engineers, scientists and academicians all over the world to endorse, discuss and share various new issues and developments in diverse areas of hydrology.
Austin Journal of Hydrology accepts original research articles, review articles, case reports, commentaries, clinical images and rapid communication on all the aspects of Hydrology.
Application of DRP scheme solving for rotating disk-driven cavityijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
Topics:
1. Introduction to Fluid Dynamics
2. Surface and Body Forces
3. Equations of Motion
- Reynold’s Equation
- Navier-Stokes Equation
- Euler’s Equation
- Bernoulli’s Equation
- Bernoulli’s Equation for Real Fluid
4. Applications of Bernoulli’s Equation
5. The Momentum Equation
6. Application of Momentum Equations
- Force exerted by flowing fluid on pipe bend
- Force exerted by the nozzle on the water
7. Measurement of Flow Rate
a). Venturimeter
b). Orifice Meter
c). Pitot Tube
8. Measurement of Flow Rate in Open Channels
a) Notches
b) Weirs
Experimental conceptualisation of the Flow Net system construction inside the...Dr.Costas Sachpazis
ABSTRACT
By means of a drainage and seepage tank, an experimental flow net system inside the body of a homogeneous earth embankment dam model, formed from Leighton Buzzard Silica sand, was developed and studied in this experimental research paper.
Water flow through dams is one of the basic problems for geotechnical engineers. Seepage analysis in an important factor to be considered in the proper design of many civil engineering structures. Seepage can occur in both through the structure itself as the case of earth dams and under foundations of an engineering structure. Successful seepage analysis is achieved on the proper and accurate construction of a flow net.
Amongst the various existing methods of seepage analysis, the “Finite Element Method” and the method of “Experimental Flow Nets” are the most widely used ones.
Construction of a flow net is mainly used for solving water flow problems through porous media where the geometry makes sometimes analytical solutions impractical. This method is usually used in soil mechanics, geotechnical or civil engineering as an initial check for problems of water flow under hydraulic structures like embankments or dams. As such, a grid obtained by drawing a series of equipotential lines and stream or flow lines is called a flow net. In this procedure the Laplace equation principles must be satisfied.
Hence, the construction of a flow net is an important tool in analysing two-dimensional irrotational flow problems and provides an approximate solution to the flow problem by following simple rules, as initially set out by Forchheimer, 1900, and later refined by Casagrande,1937. It can also be very useful tool even for problems with complex geometries, as proven in this experimental research paper.
The objectives of this experimental research paper are:
• To determine the position and shape of the flow line representing the uppermost free water surface inside the body of a dam by using a drainage and seepage tank,
• To conceptualise the flow lines system and to demonstrate that each flow line starts perpendicular to the upstream slope of the dam and that that slope is a boundary equipotential line,
• To construct an experimental flow net and subsequently to verify and analyse it by the FEA method,
• To calculate the rate of seepage through the dam body, and
• To summarise the calculations and experimental findings in a concise and readable format.
In order to achieve these objectives, an experimental flow net system inside the body of a homogeneous earth embankment dam model was formulated by using a drainage and seepage tank.
From the constructed flow net in the present experimental research paper, an attempt has been made to analyze, determine and present the following parameters:
The pressure drop from one side of the embankment to the other,
The seepage flow rate in each flow “channel”,
The total seepage flow rate, and
The pore pressure ratio, ru, for the embankment.
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
We follow "Rigorous Publication" model - means that all articles appear on IJERD after full appraisal, effectiveness, legitimacy and reliability of research content. International Journal of Engineering Research and Development publishes papers online as well as provide hard copy of Journal to authors after publication of paper. It is intended to serve as a forum for researchers, practitioners and developers to exchange ideas and results for the advancement of Engineering & Technology.
Wavelet estimation for a multidimensional acoustic or elastic earth- Arthur W...Arthur Weglein
A new and general wave theoretical wavelet estimation
method is derived. Knowing the seismic wavelet
is important both for processing seismic data and for
modeling the seismic response. To obtain the wavelet,
both statistical (e.g., Wiener-Levinson) and deterministic
(matching surface seismic to well-log data) methods
are generally used. In the marine case, a far-field
signature is often obtained with a deep-towed hydrophone.
The statistical methods do not allow obtaining
the phase of the wavelet, whereas the deterministic
method obviously requires data from a well. The
deep-towed hydrophone requires that the water be
deep enough for the hydrophone to be in the far field
and in addition that the reflections from the water
bottom and structure do not corrupt the measured
wavelet. None of the methods address the source
array pattern, which is important for amplitude-versus-
offset (AVO) studies
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Wave-Current Interaction Model on an Exponential Profileijceronline
We develop a model that approximates the exponential depth, which exhibits the behavior of linear depth particularly in the surf zone. The main effect of the present exponential depth is found in the shoaling zone, where the depth remains finite. The basic description and the outcome is essentially rip currents where in the surf zone the wave behavior is the same as found in the linear depth case. In the shoaling zone the present exponential depth exhibits the hypergeometric functions.
Application of DRP scheme solving for rotating disk-driven cavityijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
Topics:
1. Introduction to Fluid Dynamics
2. Surface and Body Forces
3. Equations of Motion
- Reynold’s Equation
- Navier-Stokes Equation
- Euler’s Equation
- Bernoulli’s Equation
- Bernoulli’s Equation for Real Fluid
4. Applications of Bernoulli’s Equation
5. The Momentum Equation
6. Application of Momentum Equations
- Force exerted by flowing fluid on pipe bend
- Force exerted by the nozzle on the water
7. Measurement of Flow Rate
a). Venturimeter
b). Orifice Meter
c). Pitot Tube
8. Measurement of Flow Rate in Open Channels
a) Notches
b) Weirs
Experimental conceptualisation of the Flow Net system construction inside the...Dr.Costas Sachpazis
ABSTRACT
By means of a drainage and seepage tank, an experimental flow net system inside the body of a homogeneous earth embankment dam model, formed from Leighton Buzzard Silica sand, was developed and studied in this experimental research paper.
Water flow through dams is one of the basic problems for geotechnical engineers. Seepage analysis in an important factor to be considered in the proper design of many civil engineering structures. Seepage can occur in both through the structure itself as the case of earth dams and under foundations of an engineering structure. Successful seepage analysis is achieved on the proper and accurate construction of a flow net.
Amongst the various existing methods of seepage analysis, the “Finite Element Method” and the method of “Experimental Flow Nets” are the most widely used ones.
Construction of a flow net is mainly used for solving water flow problems through porous media where the geometry makes sometimes analytical solutions impractical. This method is usually used in soil mechanics, geotechnical or civil engineering as an initial check for problems of water flow under hydraulic structures like embankments or dams. As such, a grid obtained by drawing a series of equipotential lines and stream or flow lines is called a flow net. In this procedure the Laplace equation principles must be satisfied.
Hence, the construction of a flow net is an important tool in analysing two-dimensional irrotational flow problems and provides an approximate solution to the flow problem by following simple rules, as initially set out by Forchheimer, 1900, and later refined by Casagrande,1937. It can also be very useful tool even for problems with complex geometries, as proven in this experimental research paper.
The objectives of this experimental research paper are:
• To determine the position and shape of the flow line representing the uppermost free water surface inside the body of a dam by using a drainage and seepage tank,
• To conceptualise the flow lines system and to demonstrate that each flow line starts perpendicular to the upstream slope of the dam and that that slope is a boundary equipotential line,
• To construct an experimental flow net and subsequently to verify and analyse it by the FEA method,
• To calculate the rate of seepage through the dam body, and
• To summarise the calculations and experimental findings in a concise and readable format.
In order to achieve these objectives, an experimental flow net system inside the body of a homogeneous earth embankment dam model was formulated by using a drainage and seepage tank.
From the constructed flow net in the present experimental research paper, an attempt has been made to analyze, determine and present the following parameters:
The pressure drop from one side of the embankment to the other,
The seepage flow rate in each flow “channel”,
The total seepage flow rate, and
The pore pressure ratio, ru, for the embankment.
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
We follow "Rigorous Publication" model - means that all articles appear on IJERD after full appraisal, effectiveness, legitimacy and reliability of research content. International Journal of Engineering Research and Development publishes papers online as well as provide hard copy of Journal to authors after publication of paper. It is intended to serve as a forum for researchers, practitioners and developers to exchange ideas and results for the advancement of Engineering & Technology.
Wavelet estimation for a multidimensional acoustic or elastic earth- Arthur W...Arthur Weglein
A new and general wave theoretical wavelet estimation
method is derived. Knowing the seismic wavelet
is important both for processing seismic data and for
modeling the seismic response. To obtain the wavelet,
both statistical (e.g., Wiener-Levinson) and deterministic
(matching surface seismic to well-log data) methods
are generally used. In the marine case, a far-field
signature is often obtained with a deep-towed hydrophone.
The statistical methods do not allow obtaining
the phase of the wavelet, whereas the deterministic
method obviously requires data from a well. The
deep-towed hydrophone requires that the water be
deep enough for the hydrophone to be in the far field
and in addition that the reflections from the water
bottom and structure do not corrupt the measured
wavelet. None of the methods address the source
array pattern, which is important for amplitude-versus-
offset (AVO) studies
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Wave-Current Interaction Model on an Exponential Profileijceronline
We develop a model that approximates the exponential depth, which exhibits the behavior of linear depth particularly in the surf zone. The main effect of the present exponential depth is found in the shoaling zone, where the depth remains finite. The basic description and the outcome is essentially rip currents where in the surf zone the wave behavior is the same as found in the linear depth case. In the shoaling zone the present exponential depth exhibits the hypergeometric functions.
Numerical Simulation and Prediction for Steep Water Gravity Waves of Arbitrar...CSCJournals
Nonlinear permanent progressive wave is one of the most important applications in water waves. In this study, analytic formulation of the steep water gravity waves is presented. Abohadima and Isobe [1] showed that Cokelet solution [2] is the most accurate among many other solutions. Due to the nonlinearity of analytic equations, the need to numeric simulation is raised up. In the current paper, consequence numerical models, using one of the artificial intelligence techniques, are designed to simulate and then predict the non linear properties of permanent steep water waves. Artificial Neural Network (ANN), one of the artificial intelligence techniques, is introduced in the current paper to simulate and predict the wave celerity, momentum, energy and other wave integral properties for any permanent waves in water of arbitrary uniform depth. The ANN results presented in the current study showed that ANN technique, with less effort, is very efficiently capable of simulating and predicting the non linear properties of permanent steep water waves.
Fluid Mechanics Chapter 4. Differential relations for a fluid flowAddisu Dagne Zegeye
Introduction, Acceleration field, Conservation of mass equation, Linear momentum equation, Energy equation, Boundary condition, Stream function, Vorticity and Irrotationality
The Effect of Bottom Sediment Transport on Wave Set-Upijceronline
In this paper we augment the wave-averaged mean field equations commonly used to describe wave set-up and wave-induced mean currents in the near-shore zone, with an empirical sediment flux law depending only on the wave-induced mean current and mean total depth. This model allows the bottom to evolve slowly in time, and is used to examine how sediment transport affects wave set-up in the surf zone. We show that the mean bottom depth in the surf zone evolves according to a simple wave equation, whose solution predicts that the mean bottom depth decreases and the beach is replenished. Further, we show that if the sediment flux law also allows for a diffusive dependence on the beach slope then the simple wave equation is replaced by a nonlinear diffusion equation which allows a steady-state solution, the equilibrium beach profile
One of marine current power plant equipment is turbine. In the design of marine current turbines required variables such as velocity and kinetic energy. This paper presents numerical study on a numerical design of marine current for predicting velocity and kinetic energy in the Bangka strait, North Sulawesi, Indonesia that developed from Yaxum/3D model. This study includes the simulation of velocity and kinetic energy distributions at low and high tide current conditions by two flow rates of 0.1 and 0.3 Sv respectively. The numerical method used to design computational program. Semi-implicit finite difference method used to 3D shallow water flow. It found distributions of velocity and kinetic energy at high tide current condition greater than low tide current condition. The future, these results will be developed in marine current power plant project in the Bangka strait, North Sulawesi, Indonesia.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology
Peristaltic flow of blood through coaxial vertical channel with effect of mag...ijmech
The present paper investigates the effects of peristaltic flow of blood through coaxial vertical channel with
effect of magnetic field: blood flow study.The effects of various physical parameters on axial velocity and
pressure gradient have been computed numerically. It is observed that the maximum velocity increases
with increase in Magnetic field (M) even though for phase shiptııııı/ 4 for all the two cases
= - 0.5,
= -1. However, opposite effects are noticed for
= 0.5,
= 1.
Ultrasonic guided wave techniques have great potential for structural health monitoring applications. Appropriate mode and frequency selection is the basis for achieving optimised damage monitoring performance.
In this paper, several important guided wave mode attributes are
introduced in addition to the commonly used phase velocity and group velocity dispersion curves while using the general corrosion problem as an example. We first derive a simple and generic wave excitability function based on the theory of normal mode expansion and the reciprocity theorem. A sensitivity dispersion curve is formulated based on the group velocity dispersion curve. Both excitability and sensitivity dispersion curves are verified with finite element simulations. Finally, a
goodness dispersion curve concept is introduced to evaluate the tradeoffs between multiple mode selection objectives based on the wave velocity, excitability and sensitivity.
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Analysis of the Interaction between A Fluid and A Circular Pile Using the Fra...IJERA Editor
The purpose of this research is to study the interaction between a fluid and a circular pile, located downstream
from a fan-shaped dam, through the fractional Navier-Stokes equations, and in particular, its approximation to
the boundary layer. The flow region is divided into zones according to the vorticity transport theory of
turbulence. First, we consider the limit of the spatial occupancy index close to 1. Then, a stream function is
introduced, and for the potential zone, we consider a complex potential, using the inverse distances on a circle.
In the other limit, when the spatial occupation index approaches 0, we consider the equations of the boundary
layer in the limit of fully developed turbulence. Next, for the last approaches, a new stream function and
velocities in their radial and polar components are obtained. We also find the asymmetry of the pressure
distribution around the pile, based on the viscosity and considering that the pressure drag force and the friction
coefficients are proportional to the inverse of the Reynolds number. We conclude that D'Alembert's paradox and
Thomson's theorem has been resolved. For applications, in the case of the turbulent wake, we are interested both
in the orientation given by the pile symmetry axis and its extension. The criterion that should be satisfied is: the
diameter of the pile, on the border of inequality, must be located as proportional average between the length of
the turbulent wake and twice the characteristic length associated with the dam, whose aspect ratio, in turn, to the
pile diameter, determines the contraction factor.
Recent Advancement and Patents of the Lipid Polymer Hybrid Nanoparticlespeertechzpublication
In recent years, robustness and surface engineering of dosage form made improvement in
pharmacokinetics with decrease in dose of drug. Specifi city with adherence of ligands has now become
the reality as surface modifi cation can easily deceive phagocytic system. Lipid molecules ensures the
release of drug at lymphatic system, entrapment of polymeric nanoparticles in lipoidal core led to the
avoidance of disadvantage of low entrapment effi ciency if use of hydrophobic drug with hydrophobic
polymer becomes essential. Various studies have been published and the best formulations with optimal
In vitro and In vivo results are highlighted in this paper. In this review most advanced researches and
accepted patents were discussed so to act as a medium for getting everything regarding lipid polymer
hybrid particles under one umbrella.
Vibrational Characterization and Antioxidant Activity of Newly Synthesized Ga...peertechzpublication
The gallium(III) complex of orotic acid (HOA) was synthesized and its structure was determined
by means of analytical and spectral analyses. Detailed vibrational analysis of HOA, sodium salt of HOA
(NaOA) and Ga(III)-OA systems based on both the calculated and experimental spectra confi rmed the
suggested metal-ligand binding mode. Signifi cant differences in the IR and Raman spectra of the complex
were observed as compared to the spectra of the ligand and confi rmed the suggested metal-ligand
binding mode.
Synthesis and Antimicrobial Evaluation of Some Nitro-Mannich Bases Derived fr...peertechzpublication
The present work focused on exploring the reactivity of β-nitrostyrene towards Mannich reaction
with different approaches. The synthesized nitro-Mannich bases were tested as antimicrobial agents
that showed high activity against both gram positive and gram negative bacteria.
Recent Structure Activity Relationship Studies of 1,4-Benzodiazepinespeertechzpublication
Structure activity relationship studies of 1,4-benzodiazepines have been discussed especially
with their effects as antianxiety and anticonvulsants. The currently available benzodiazepines are
associated with various side effects. Nowadays the purpose of these studies is to minimize side effects
with these drugs. A very little alteration is possible on the benzene ring while the modification can be
done on the diazepine ring. It can adopt the different conformations and in some cases some aromatic
and heterocyclic rings have been fused with this part in order to see the effect of these conformation
blockers on the pharmacological activity. The structure activity studies are also linked to molecular
modeling studies. This is important in adding some information for the interaction of these drugs with
the receptors and how this interaction can be improved.
Microwave Irradated Synthesis, Characterization and Evaluation for their Antibacterial and Larvicidal Activities of some Novel Chalcone and Isoxazole Substituted 9-Anilino Acridines
drug delivery and formulation sciences in the most intelligent
way. This should be attained to fulfi l the ultimate goal for all
scientists to leave their experimental results all over the years
as footsteps for followers to walk on.
Mycobacterium Tuberculosis cause severe disease of lungs known as Tuberculosis. It is a major cause
of morbidity and mortality even in the emerging countries also. However, to prepare an antibiotics drug against Mycobacterium tuberculosis is a major challenge
Mini tablets are solid dosage forms with a diameter ≤ 3 mm and separated into subunits of conventional
tablets. Production methods are similar to standard tablets, but the only difference is the use of multiple
punches. They have advantageous for use in patients suffering from swallowing difficulty and receiving multiple drug treatment.
Drug-Drug interactions (DDI) is a serious clinical issue. An important mechanism underlying of DDI, is
induction or inhibition of drug metabolizing enzymes (DMEs) and transporters that mediate metabolism, cellular uptake and efflux of xenobiotics. DDI cannot be avoided in many cases, as they belong to routine medical practice.
In recent years, robustness and surface engineering of dosage form made improvement in pharmacokinetics with decrease in dose of drug. Specificity with adherence of ligands has now become the reality as surface modifi cation can easily deceive phagocytic system. Lipid molecules ensures the
release of drug at lymphatic system, entrapment of polymeric nanoparticles in lipoidal core led to the
avoidance of disadvantage of low entrapment effi ciency if use of hydrophobic drug with hydrophobic polymer becomes essential. Various studies have been published and the best formulations with optimal In vitro and In vivo results are highlighted in this paper. In this review most advanced researches and accepted patents were discussed so to act as a medium for getting everything regarding lipid polymer hybrid particles under one umbrella.
Few species are standardized and have been used as test organisms around the world in
ecotoxicological assays. In the case of sediment assessment, there are only two amphipod species
(Tiburonella viscana and Grandidierella bonnieroides) standardized protocols for toxicity test in South
Atlantic region
Gigantic submarine landslides are among the most energetic events on the Earth surface. During the
Late Pleistocene the Mediterranean Sea was the scenario of a 9 number of such events, some of whose
geological fi ngerprints are the 500 km3 mass transport deposit SL2 at the Nile delta fan (dated at ca. 110
ka BP) and the Herodotus Basing Megaturbidite (HBM, a 400 km3 deposit dated at ca. 27.1 ka BP).
Natural frequency of structure mainly depends on mass and stiffness. Stiffness is bound to change
after structural damage. Hence, natural frequency starts to decline.
In this study, the green-lipped mussels Perna viridis were collected from a high activity sampling at
Senibong in the Straits of Johore and two relatively clean sites with fi sh aquacultural activity at Bagan
Tiang (Perak) and Sg. Semerak (Kelantan). The mussels were dissected by gender into byssus, crystalline
style, foot, gill, gonad, mantle and muscle.
The growth of data and its effi cient handling is becoming more popular trend in recent years bringing
new challenges to explore new avenues. Data analytics can be done more effi ciently with the availability of
distributed architecture of “Not Only SQL” NoSQL databases.
In modern mechanical engineering and steelwork the use of cold-rolled steel sections is a
standard method. These sections should be mechanically stable on the one hand and cost efficient on
the other hand. To decide what profile suits for a certain case is a constrained optimization problem which is in general non convex, i.e. several local optima exist.
Few species are standardized and have been used as test organisms around the world in
ecotoxicological assays. In the case of sediment assessment, there are only two amphipod species
(Tiburonella viscana and Grandidierella bonnieroides) standardized protocols for toxicity test in South
Atlantic region.
Gigantic submarine landslides are among the most energetic events on the Earth surface. During the
Late Pleistocene the Mediterranean Sea was the scenario of a 9 number of such events, some of whose
geological fi ngerprints are the 500 km3 mass transport deposit SL2 at the Nile delta fan (dated at ca. 110
ka BP) and the Herodotus Basing Megaturbidite (HBM, a 400 km3 deposit dated at ca. 27.1 ka BP). This
paper presents an exploratory study on the tsunamigenic potential of these slides by using a numerical
model based on the 2D depth-averaged non-linear barotropic shallow water equations.
Introduction: The aim of this study is to evaluate, within the scope of an experimental design, to
what extent the assessment of two different settings of prepared cavities, based on video sequences,
containing digital analysis tools of the prepCheck software, as well as to what extent they deviate from one another and are reliable. Materials and Methods: For
Predicting the amount of electricity produced in a power plant is very important for today’s economy.
Oven Power (MW), Boiler Input Gas Temperature, Superheated Steam Amount, ID-Fan Speed, Feeding
Water Tank data affect the electricity production.
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
How to Give Better Lectures: Some Tips for Doctors
Annals of Limnology and Oceanography
1. vv
Annals of Limnology and Oceanography
DOI CC By
013
Citation: Farhadi A (2016) Simulating Solitary Wave Generation Using Incompressible SPH. Ann Limnol Oceanogr 1(1): 013-021.
Life Sciences Group
Abstract
The current study examines the generation and propagation of a Third order solitary water wave along
the channel. Surface displacement and wave profile prediction challenges are interesting subjects in the
field of marine engineering and many researchers have tried to investigate these parameters. To study the
wave propagation problem, here, firstly the meshless Incompressible Smoothed Particle Hydrodynamics
(ISPH) numerical method is described. Secondly, the boundary condition handling method, discretization,
timestep selection and geometry provitions are presented. The numerical model is then used to simulate
solitary wave propagation along the fixed depth channel. Here two still water depths of h = 0.2 m and h
= 0.3 m are assumed and the dimensionless height of desired wave ranging from = 0.1 to = 0.6 are
simulated. The numerical results show that studied Grimshaw Third order method can track the wave
profile and it has acceptable relative variation for 5 seconds after the wave propagation, about 10%. In
general, the numerical model gives satisfactory results for the wave kinematics.
Research Article
Simulating Solitary Wave Generation
Using Incompressible SPH
Asghar Farhadi*
Young Researchers and Elite Club, Shiraz Branch,
Islamic Azad University, Shiraz, Iran
Dates: Received: 01 December, 2016; Accepted: 13
December, 2016; Published: 15 December, 2016
*Corresponding author: Asghar Farhadi, Young
Researchers and Elite Club, Shiraz Branch,
Islamic Azad University, Shiraz, Iran, E-mail:
Keywords: ISPH; Kernel function; Outskirts decay co-
efficient; Solitary wave; Wave celerity
https://www.peertechz.com
Introduction
Over the past few decades, offshore structures, such as
oil platforms, offshore wind-power plants, have been in
rapid growth in coastal and deep ocean regions, and wave-
structure interaction has long been a strong interest in coastal
and offshore engineering. A thorough understanding of the
interaction of waves with offshore structures is vital in the safe
and design of such structures. In addition, the flow field near
the structures is helpful to understand the scour, sediment
transport process in the coastal regions. In designing these
structures, it is critical to be able to calculate wave forces acting
on each individual structure.
Information on wave forces can be obtained by means
of laboratory experiments or numerical simulations. Since
laboratory experiments are usually constrained by the physical
dimensions of laboratory facilities, it is not very often feasible
to perform extensive parameter studies (e.g., variation of
water depth, wave parameters, breaker type, etc.) even if the
costs are of no concern. The alternative is to use numerical
simulations as supplements to laboratory experiments, where
accurate numerical simulations will also provide much more
detailed insights into the physical processes that could not be
achieved by experimental approach. In other words, a limited
numbers of experiments can be designed so that the laboratory
data can be effectively used to validate numerical models. The
validated numerical models are then used to simulate scenarios
with much wider range of physical parameters of interest.
So far, wide range of the numerical simulation models
developed for wave propagation as the key concept in the
maritime engineering which have been built upon the Navier-
Stokes equations. One of these methods is the SPH method
that has gradually matured over time into a suitable tool
for computational fluid dynamics because of its flexibility
to simulate complex problems such as flow through porous
medium [1], multi-phase flows [2-4], heat conduction [5],
free surface problems [6-8], fluid structure interactions
[9,10], fuel cell [11], etc. However, compared with the Finite
Difference (FD) or Finite Volume (FV) methods, SPH is still a
relatively novel method in computational fluid dynamics and
its shortcomings are still being improved. Shao and Lo [12],
introduced ISPH algorithm based on the projection scheme.
Numerical results have shown that ISPH produces reasonable
accurate predictions of velocity and forces on solids.
Solitary wave generation is a traditional benchmark for
numerical wave model tests. It is a permanent progressing wave
form consisting of a single elevation above the undisturbed
surface that propagates without the change of form on a
constant still water depth over a flat bottom. A wide variety of
analytical theories have been introduced for the solitary wave
generation. It was first reported by Russell [13], who made
remarkable experiments and gave an empirical relationship
for the wave speed, which was later established theoretically,
to the lowest order by Boussinesq [14] and Rayleigh [15], as
part of an overall approximate solution. Since then, there have
been several attempts to improve upon this solution, e.g. see
2. Farhadi (2016)
014
Citation: Farhadi A (2016) Simulating Solitary Wave Generation Using Incompressible SPH. Ann Limnol Oceanogr 1(1): 013-021.
[16-18]. Of the approximate solutions, several methods for
the solitary wave have obtained series expansions in terms
of wave amplitude, these being taken as far as the third order
Grimshaw. He considered the one-dimensional modulations
formed on the Boussinesq solitary wave and obtained third
order equations analogous to those used by Boussinesq for
the case of constant undisturbed depth in the higher order
form [19]. Furthermore, an asymptotic solution was presented
which described a slowly varying solitary wave [20]. An early
work on WCSPH for solitary wave was done by Monaghan [21],
while Lo and Shao used ISPH to generate solitary waves [22]. In
this study, an ISPH method will be used to simulate the solitary
wave generation and propagation in constant water depth.
Governing equations
The motion of a continuum in the Lagrangian description
subjected to the action of body force in the isothermal condition,
is represented by the continuity equation:
i
i
vD
Dt x
(1)
and the momentum equation:
1 iji
i
j
Dv
f
Dt x
(2)
Where p is density, t is time, vi
is the velocity vector, xi
is
the position vector, fi is the body force vector, ij
is the stress
tensor and the notation implies summation over repeated
indices. The stress tensor can be decomposed into deviatoric
viscous stress tensor ij
and isotropic pressure p, according to
the following equation:
ij ij ijp (3)
Where ij
is the Kronecker delta. Pressure can be formally
defined by the equation of state in the compressible flows, while
for incompressible flows, it is derived from the divergence free
condition of the velocity field. Assuming an incompressible
Newtonian fluid, the continuity Equation (1) reduces to:
. 0u
(4)
and the momentum Equation (2) will be:
D 1
.
Dt
u
p v u F
(5)
Where is the kinematic viscosity. The conventional
incompressible approach deals with pressure and velocity as
primitive variables. The classical projection method [23] is used
to calculate the pressure field and enforce incompressibility,
simultaneously. The discretized form of the momentum
equation is split into two parts. The first being the prediction
step and is based on viscous and body forces. In this step, the
intermediate velocity field *
u
is obtained from velocity at (n)
th
time step:
*
.
n
n
u u
u F
t
(6)
In each time step, the intermediate velocity field is
calculated for fluid and boundary particles. In the second step,
correction step, pressure force is included:
1 *
1
1
n
n
u u
p
t
(7)
The intermediate velocity field is usually not divergence
free but this is imposed upon
1n
u
. Hence, the intermediate
velocity is projected on the divergence free space by taking the
divergence of Equation (7) as:
*
12
.
n
u p
t
(8)
where the 2
is the Laplacian operator. Once the pressure
is obtained from pressure Poisson Equation (8), the velocity
vector is updated by using the computed new pressure gradient:
1 *
11
n
n
u u p t
(9)
Finally, particles are moved according to this corrected
velocity as:
1
1
n
n n
r r u t
(10)
SPH interpolation
The foundation of mesh free SPH method is based on
integral interpolants which represents that any field variable
X can be calculated over a set of SPH particles on domain of
interest in terms of its values by taking a good interpolation
kernel function. The exact integral representation of field
variable X is:
' ' '
X X d
r r r r r (11)
Where (r – r′) is Dirac delta function and Ω represents the
computational domain. Equation (11) can be represented by
defining a proper kernel function, W, with effective smoothing
length h as:
' ' '
X X W d
r r r r r (12)
In discrete notation, this approximation leads to the
following approximation of the function at a interpolation
particle a:
X
X b
b ab
bb
r m W
(13)
where b is all the particles within the kernel function’s
support domain. mb
and pb
are the mass and density of particle
b, respectively, and weight function or kernel is denoted by
,a babW W r r h
.
The parameter h is influence domain or smoothing domain,
and controls the size of the area around particle a where
contribution from the rest of the particles cannot be neglected.
Considering the computational accuracy and efficiency [24],
the following kernel function based on the cubic spline function
and normalized in two dimensional is adopted:
3. Farhadi (2016)
015
Citation: Farhadi A (2016) Simulating Solitary Wave Generation Using Incompressible SPH. Ann Limnol Oceanogr 1(1): 013-021.
(14)
where for two dimensional cases 2
10 / 7D h . The
gradient, divergence and Laplacian operators need to be
formulated in ISPH algorithm. In the current work, the
following commonly used forms are employed for gradient of
a scalar A [25]:
2 2
a b
aa a b ab
b a b
A A
A m W
(15)
and divergence of a vector u* [26]:
* *1
. .a ab ab ab
a b
u m u W
(16)
where a abW
is the gradient of the kernel function with
respect to particle a and calculated as:
a b h ab
a h ab
ab ab
W rx x
W r
r r
(17)
Viscous term is discretized according to the relation given
in [5]:
2 0
0 2
2
16 v .
v
ab ab
ab ab
a bba
ab
r
m W
r
(18)
where ab a bA A A
and 2 2
0.01h is a parameter to
avoid a zero denominator. Also Laplacian equation is discretized
according to the relation given in [27]:
2
2
2
.ab aa b ab
b ab
a a bb
ab
r W
p m p
r
(19)
Resolution of the linear systems are widely studied by
mathematicians as the demand for an efficient and smoothly-
converging solver increases from numerical simulations.
There are numerous iterative methods that are widely used in
academic and commercial codes to solve the Pressure Poisson
Equation (PPE). Here two solvers, Conjugate Gradient (CG) and
Bi-Conjugate Gradient (Bi-CG) [28,29], can be applied to solve
PPE.
The computational domain is divided into square cells
of side 2h. Thus, for a particle located inside a cell, only
the interactions with the particles of the same cell and its
neighbors need to be considered (only 9 cells in 2-D). The
searching algorithm is applied at the beginning of each time
step updating the particle’s neighbors and the corresponding
kernel derivatives. The time step limit for this method is the
minimum of three conditions, the CFL, the mass and the
viscous force conditions such that [26]:
2
, ,
a a aref
h h h
t min
fu
(20)
where fa
is the force per unit mass, equivalent to the
magnitude of particle acceleration and uref
is the maximum
fluid velocity in the domain [26].
Boundary condition handling
The Lagrangian nature of SPH method will cause the
implementation of the boundary conditions less straightforward
than in common mesh based methods. Different boundary
conditions are used in the SPH method. In the present study,
moving and stationary solid wall boundary conditions are used.
There are different boundary types in SPH to simulate solid
walls, namely the repulsive force [30], ghost or mirror particles
[31] and dummy particles [12,32]. The repulsive force boundary
condition, first proposed by Monaghan [30], uses forces similar
to inter-molecular interactions. A force is exerted on a fluid
particle having a distance r from a boundary particle, which has
the form of Lennard-Jones potential. This force is increased
as the distance r between a boundary and a fluid particle is
decreased, preventing the fluid particles from penetrating the
wall, Figure 1.
The mirror particle method is used to enforce the no-
slip as well as the Neumann boundary conditions. In this
method the particles whose support domain is truncated by
a solid boundary are reflected on the other side of the wall.
The mirror or ghost particles have the same pressure as their
corresponding fluid particles but have velocities extrapolated
from the fluid and wall velocities.
One of the sources of inaccuracy in the SPH method is
the truncation of the boundary particles. This means that,
not enough particles might be present in the support domain
of a fluid particle. The other method to model solid walls is
the use of dummy particles. In this method several layers of
dummy particles are placed parallel to the boundary particles.
So, the support domain of the particles located close to the
solid wall will not be truncated any longer. These layers of
dummy particles are linked to their corresponding boundary
particles and have the same pressure and velocity as their
linked particles. In the present work, dummy particles are used
to model solid walls.
The number of dummy particle layers are decided from the
Figure 1: Sketch of repulsive force boundary condition.
2 3
3
3 3
1 0 1
2 4
1
, 2 1 2
4
0 2
D
q q q
W q h q q
q
4. Farhadi (2016)
016
Citation: Farhadi A (2016) Simulating Solitary Wave Generation Using Incompressible SPH. Ann Limnol Oceanogr 1(1): 013-021.
radius of the compact support. In the following simulations,
three layers of dummy particles are used. Governing equations
are solved only for fluid and boundary particles and the pressure
and velocity (also intermediate velocity) of the dummy particles
are updated to their corresponding boundary wall particles.
The velocity and the intermediate velocities are held
constant on the boundary particles, but their pressure is
calculated from the PPE equation. Afterwards, the pressure
of the dummy particles are updated to their corresponding
boundary particles. In this way the Neumann boundary
condition on the walls is approximated.
Wave characteristics
Three key parameters to identify waves are their lengths and
heights, and the water depth over which they are propagating.
All other parameters can be calculated from these quantities,
e.g. wave induced water accelerations and velocities. A two
dimensional schematic of a wave propagating in the x direction
is shown in the Figure 2. The wave length, , is the horizontal
distance between two successive wave troughs. This length is
related to the water depth,h, and wave period, T, which is the
time required for two successive troughs to pass a particular
point. As the wave moves a distance , in time T, its speed
called celerity is defined as C =/ T.
Solitary waves in constant water depth
Two dimensional dam break flow is chosen as the first
suitable validation test case. Dam break flows over dry and
wet beds have attracted wide research areas due to their
theoretical, engineering and scientific considerations. If a dam
break occurred over a dry bed, the generated wave is described
by a tongue of water extended rapidly along the dry bed and if
dam flows toward downstream over the wet bed, the attributed
fluid flow features become remarkably different and some
vorticity is developed at the front of the dam break. As a result,
characteristics of the fluid flow are represented by the wave
generation, wave crest development, wave breaking, and its
impact with the downstream calm water and strew of water
that generates some splash-up flow. Due to these features,
dam break over the wet bed is an interesting benchmark to
validate the numerical methods [33,34].
Solitary wave propagation in constant water depth is a
classical benchmark problem for numerical wave model test.
It propagates without the change of form in constant water
depth over a flat bottom. Different analytical theories are
already developed for the solitary wave. Therefore, it is well
suited to evaluate the accuracy of the numerical model. For
example, by checking the free surface location, the quality of
volume tracking algorithm can be evaluated. In the numerical
simulation, the free surface elevation and velocity distribution
prescribed on the incident wave boundary are calculated by
Third-order Grimshaw solitary wave solution [20,35]:
2 2 2 2 3 2 2 4 23 5 101
,
4 8 80
x t h s s q s q s q
(21)
where = H/h; H is the wave height; h is the still water
depth; /s sech X h ; /q tanh X h ; X x Ct in which C
is the wave speed; the coefficient :
(22)
and the wave speed C is:
0.5
2 31 3
1
20 70
C gh
(23)
and the velocity distribution is:
2 2
2
2 2 2 2 2 2
2
2 2 2 4 2 2 2 2 4 2
3
4
2 4 2
3 3 9
4 4 4
21 6 9 15 15
40 5 4 4 2
3 45
8 16
u
s
gh
z
s s q s s q
h
z
s s q s q s s q s q
h
z
s s q
h
2
2
2 2 2
2
2 4 2 4
3
4
2 4
3
3 1 3
2
8 2 2
49 17 18 13 25 15
640 20 5 16 16 2
3 9 27
40 8 16
w z
s q
hgh
z
s s
h
z
s s s s
h
z
s s
h
(24)
The coordinate system is defined in Figure 3. The Grimshaw
solution is well suited for solitary wave of 0.5 .
The Third order Grimshaw solitary waves is simulated to
be compared with the analytical theory. Here two still water
depths of h=0.2 m and h=0.3 m are assumed (Figure 4) and the
Figure 2: Schematic wave representation.
Figure 3: Solitary wave representation.
23 5 71
1
4 8 128
5. Farhadi (2016)
017
Citation: Farhadi A (2016) Simulating Solitary Wave Generation Using Incompressible SPH. Ann Limnol Oceanogr 1(1): 013-021.
dimensionless height of desired wave ranging from to
h = 2.0 m are simulated, where particle resolution of 37000 and
77000 are used for the water depths of h=0.2 m and h=0.3 m,
respectively. The computational domain is 50h in the stream
wise direction x and 2h in the vertical direction y. In the stream
wise direction, 1260 and 1860 particles with uniform grid size
of 0.008 r m are used, while we use 50 and 75 particles
in the vertical direction in two cases, respectively. The fluid
has a density of 3
1000 /kg m and kinematic viscosity of
6 2
1 10 /m s
.Three layers of dummy particles are used to
handle the wall boundary condition.
Figure 5 shows the free surface elevation profiles at three
different times (1, 3 and 5 seconds from beginning of the
simulation) corresponding to solitary waves generated using
the Third order Grimshaw method for a water column with
0.3 h m and 0.4 . It is noticeable that compared with the
analytical solution, the wave profile heights are decreased as
it follows throughout the channel. The discrepancy between
the predicted and analytical heights are 10% when the wave
propagates along the channel for first 5 seconds.
On Figure 6(a), the paddle laws of motion corresponding
to the Third order wave generation is plotted for 0.4 for
a water column with 0.3 h m . Greatest accelerations occur
somewhere between the beginning of motion (zero velocity)
and mid-stroke (maximum velocity). Qualitatively, the larger
the maximum velocity and the shorter the duration of motion,
the greater the acceleration. For the same wave we also plot on
Figure 6 (b) the dimensionless paddle velocity corresponding
to this law of motion. The maximum nondimensionalized
velocity of 0.27 is observed.
Measurements of the free surface elevation at different
distances from the paddle for a solitary wave of desired
dimensionless amplitude 0.2 in a water column of
0.2 mh where was generated using Third order numerical
integration are plotted on Figure 7. The solitary wave amplitude
is decreases slowly as it travels along the channel.
Figure 8 shows the nondimensionalized velocity component
variations versus nondimensionalized vertical coordinate of
the wave at 1.5 t s from the beginning of the simulation
for two locations ( 2 x m and 3 x m regarding the initial
Figure 4: Initial particle distribution of solitary wave generation test case for h =
0.2 m h=0.2 m.
Figure 5: Solitary wave profile comparisons with analytic ones at various times for
ε=0.4 and a water column of h=0.3 m
Figure 6: Paddle motion for E = 0.2 and a water column of h=0.3 m
paddle location). The velocity profiles are close to the analytic
ones. Near the water surface, under both wave surfaces, the
measured particle horizontal velocity is somewhat greater than
the theoretical values, while the vertical velocity components is
underestimated compared with the analytic ones, the reason of
which may be due to the particle resolution.
The flow field contours at three different times are
illustrated in Figures (9-11) for the 0.3 case for a water
column of . As seen, the pressures are captured precisely
and the pressure distributions under the wave crests are
accurately predicted, Figure 9. The wave speed at this case is
1.59 /C m s , that proves the wave crest propagation at these
selected times, where the wave crest transferred to x = 2.61 m,
x = 5.83 m and x = 9.05 m, respectively, Figure 10. Furthermore,
the symmetric behavior of the vertical velocity at the wave is
noticeable at these selected times, Figure 11.
0.2 h m
0.3
6. Farhadi (2016)
018
Citation: Farhadi A (2016) Simulating Solitary Wave Generation Using Incompressible SPH. Ann Limnol Oceanogr 1(1): 013-021.
Figure 7: Comparison of record of free surface elevation at different distances
from the paddle with analytic ones.
Figure 8: Comparisons of velocity components with analytical results at t=1.5 s at
different distances away from the paddle initial location.
Figure 9: Solitary wave pressure contour.
Figure 10: Solitary wave horizontal velocity contour.
7. Farhadi (2016)
019
Citation: Farhadi A (2016) Simulating Solitary Wave Generation Using Incompressible SPH. Ann Limnol Oceanogr 1(1): 013-021.
Figure 11: Solitary wave vertical velocity contour.
Figure 12: Maximum paddle velocity and displacement for a solitary wave with
h=0.3 m
In order to investigate the solitary wave generated behavior
on the pureness of the generated wave on other wave heights,
this problem is solved for a wide range of the desired wave
heights, 0.1 0.6 . As expected, greater the desired wave
height, the greater amount of the water volume must be
pushed. Figure 12(a) illustrates the depth averaged net mass
displacement L of a solitary wave. This net mass displacement
is the total stroke of the paddle prescribed in each procedure.
The rate of the displacement increment is decreased as the
desired wave height is increased. Furthermore, the maximum
paddle velocity (which occurs at mid-stroke) is obtained for
this range of wave heights. Again, the slope of the maximum
paddle velocity is decreases as dimensionless amplitude
increases.
The dimensionless phase speed (or Froude number,
/F C gh ) is plotted on Figure 13(a) for the selected wave
height range. It shows that the Third order method phase
speed is matches to the Byatt-Smith numerical estimation
in the studied range of . The dimensionless outskirts decay
coefficient 2 . h versus the dimensionless amplitude
is plotted on Figure 13(b). This outskirts decay coefficient
describes the way free surface elevation tends towards the
mean level at infinity. Stokes showed that is a solution of the
following equation, also used by Byatt-Smith [36]:
2 tan
F
(25)
Figure 13: Wave parameters for a solitary wave with h=0.3 m. The Byatt-Smith’s
numerical solution [36] is plotted as stars.
8. Farhadi (2016)
020
Citation: Farhadi A (2016) Simulating Solitary Wave Generation Using Incompressible SPH. Ann Limnol Oceanogr 1(1): 013-021.
As a matter of fact the Third order method for 0.4
matches the Byatt-Smith reference but for greater some
discrepancy is observed.
Conclusion and Future Works
The ISPH numerical method is used to simulate the
solitary wave generation and propagation along the channel at
different wave amplitudes and water depths in an ISPH-based
numerical wave flume. The numerical results are compared
with analytical data in terms of free surface displacements,
fluid particle velocity, phase speed, flow field counters and
some other wave parameters.
In the first section, the free surface profile variations over
time, position and through solitary wave amplitude ranges are
assumed. The numerical free surface profiles are compared
with analytical results at various times and it is proved that
studied Grimshaw Third order method has acceptable relative
variation for 5 seconds after the wave propagation, about 10%.
In the second section, solitary wave paddle motions, paddle
velocities and accelerations, their displacements, phase speeds
and outskirts decay coefficients are assumed. Results were in
a good agreement with the analytical data. Then, maximum
paddle velocity and displacement of the wave generation
procedures are derived and as seen they coincide with the
analytical data. Based on the obtained results, I am continuing
this methodology in the two solitary waves runup, the C-wave
in sloped beachesm ship motions in the regular waves and
breaking criteria for two solitary waves investigations in the
in-hand studoes.
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