scholarly journals Simulating Nearshore Wave Processes Utilizing an Enhanced Boussinesq-Type Model

Modelling ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 686-705
Author(s):  
Anastasios Metallinos ◽  
Michalis Chondros ◽  
Andreas Papadimitriou
Keyword(s):  
Wave Propagation ◽  
Wave Field ◽  
Real Life ◽  
Wave Model ◽  
Coastal Areas ◽  
Type Model ◽  
Wave Overtopping ◽  
Daunting Task ◽  
Wide Range ◽  
Computational Resources

The simulation of wave propagation and penetration inside ports and coastal areas is of paramount importance to engineers and scientists desiring to obtain an accurate representation of the wave field. However, this is often a rather daunting task due to the complexity of the processes that need to be resolved, as well as the demanding levels of required computational resources. In the present paper, the enhancements made on an existing sophisticated Boussinesq-type wave model, concerning the accurate generation of irregular multidirectional waves, as well as an empirical methodology to calculate wave overtopping discharges, are presented. The model was extensively validated against 4 experimental test cases, covering a wide range of applications, namely wave propagation over a shoal, wave penetration in ports through a breakwater gap, wave breaking on a plane sloping beach, and wave overtopping behind breakwaters. Good agreement of the model results with all experimental measurements was achieved, rendering the wave model a valuable tool in real-life applications for engineers and scientists desiring to obtain accurate solutions of the wave field in wave basins and complex coastal areas, while keeping computational times at reasonable levels.

REEF3D::FNPF—A Flexible Fully Nonlinear Potential Flow Solver

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Hans Bihs ◽  
Weizhi Wang ◽  
Csaba Pakozdi ◽  
Arun Kamath
Keyword(s):  
Wave Propagation ◽  
Free Surface ◽  
Wave Model ◽  
Surface Boundary ◽  
Wave Fields ◽  
Flow Solver ◽  
Surface Boundary Conditions ◽  
Nonlinear Potential ◽  
Numerical Wave ◽  
Computational Resources

Abstract In situations where the calculation of ocean wave propagation and impact on structures are required, fast numerical solvers are desired in order to find relevant wave events. Computational fluid dynamics (CFD)-based numerical wave tanks (NWTs) emphasize on the hydrodynamic details such as fluid–structure interaction, which make them less ideal for the event identification due to the large computational resources involved. Therefore, a computationally efficient numerical wave model is needed to identify the events both for offshore deep-water wave fields and coastal wave fields where the bathymetry and coastline variations have strong impact on wave propagation. In the current paper, a new numerical wave model is represented that solves the Laplace equation for the flow potential and the nonlinear kinematic and dynamics free surface boundary conditions. This approach requires reduced computational resources compared to CFD-based NWTs. The resulting fully nonlinear potential flow solver REEF3D::FNPF uses a σ-coordinate grid for the computations. This allows the grid to follow the irregular bottom variation with great flexibility. The free surface boundary conditions are discretized using fifth-order weighted essentially non-oscillatory (WENO) finite difference methods and the third-order total variation diminishing (TVD) Runge–Kutta scheme for time stepping. The Laplace equation for the potential is solved with Hypre’s stabilized bi-conjugated gradient solver preconditioned with geometric multi-grid. REEF3D::FNPF is fully parallelized following the domain decomposition strategy and the message passing interface (MPI) communication protocol. The numerical results agree well with the experimental measurements in all tested cases and the model proves to be efficient and accurate for both offshore and coastal conditions.

Propulsive jets and their acoustics

2007 ◽  
Vol 365 (1859) ◽  
pp. 2443-2467 ◽  
Author(s):  
Alexander N Secundov ◽  
Stanley F Birch ◽  
Paul G Tucker
Keyword(s):  
Navier Stokes ◽  
Jet Flows ◽  
Complex Flow ◽  
Flow Physics ◽  
Eddy Simulation ◽  
Daunting Task ◽  
Wide Range ◽  
Large Eddy ◽  
Computational Resources ◽  
Hybrid Forms

The complex flow physics challenges and asks questions regarding these challenges a wide range of jet flows found in aerospace engineering. Hence, the daunting task facing Reynolds-averaged Navier–Stokes (RANS) technology, for which the time average of the turbulent flow field is solved, is set out. Despite the clear potential of large eddy simulation (LES)-related methods and hybrid forms involving some RANS modelling, numerous current deficiencies, mostly related to the limitations of computational resources, are identified. It is concluded that currently, these limitations make LES and hybrids most useful for understanding flow physics and refining RANS technology. The use of LES in conjunction with a ray-tracing model to elucidate the physics of acoustic wave transmission in jets and thus improved RANS technology is described. It is argued that, as a stopgap measure, pure RANS simulations can be a valuable part of the design process and can now predict acoustics spectra and directivity diagrams with useful accuracy. Ultimately, hybrid RANS–LES-type methods, and then pure LES, will dominate, but the time-scales for this transition suggests that improvements to RANS technology should not be ignored.

scholarly journals A RENORMALIZATION APPROACH TO REACTION-DIFFUSION PROCESSES ON FRACTALS

Fractals ◽  
2003 ◽  
Vol 11 (04) ◽  
pp. 315-330 ◽  
Author(s):  
JANAN ABDULBAKE ◽  
ANTHONY J. MULHOLLAND ◽  
JAGANNATHAN GOMATAM
Keyword(s):  
Wave Propagation ◽  
Diffusion Processes ◽  
Travelling Waves ◽  
Reaction Diffusion ◽  
Type Model ◽  
Fractal Structures ◽  
Fractal Media ◽  
Wide Range ◽  
Renormalization Approach ◽  
Physical Phenomena

Of fundamental importance to wave propagation in a wide range of physical phenomena is the structural geometry of the supporting medium. Recently, there have been several investigations on wave propagation in fractal media. We present here a renormalization approach to the study of reaction-diffusion (RD) wave propagation on finitely ramified fractal structures. In particular we will study a Rinzel-Keller (RK) type model, supporting travelling waves on a Sierpinski gasket (SG), lattice.

WAVE CLIMATE OF THE BLACK SEA’S COASTAL WATERS DURING THE LAST THREE DECADES

2017 ◽  
Author(s):  
Fedor Gippius ◽  
Fedor Gippius ◽  
Stanislav Myslenkov ◽  
Stanislav Myslenkov ◽  
Elena Stoliarova ◽  
...  
Keyword(s):  
Wind Speed ◽  
Cell Size ◽  
Coastal Waters ◽  
Wind Wave ◽  
Spatial Scales ◽  
Wave Model ◽  
Wave Climate ◽  
Computational Grid ◽  
Coastal Areas ◽  
Wave Parameters

This study is focused on the alterations and typical features of the wind wave climate of the Black Sea’s coastal waters since 1979 till nowadays. Wind wave parameters were calculated by means of the 3rd-generation numerical spectral wind wave model SWAN, which is widely used on various spatial scales – both coastal waters and open seas. Data on wind speed and direction from the NCEP CFSR reanalysis were used as forcing. The computations were performed on an unstructured computational grid with cell size depending on the distance from the shoreline. Modeling results were applied to evaluate the main characteristics of the wind wave in various coastal areas of the sea.

A MODELING SYSTEM FOR CLIMATE CHANGE RISK ASSESSMENT, MANAGEMENT AND HEDGING IN COASTAL AREAS

2017 ◽  
Author(s):  
Sergei Soldatenko ◽  
Sergei Soldatenko ◽  
Genrikh Alekseev ◽  
Genrikh Alekseev ◽  
Alexander Danilov ◽  
...  
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Coastal Areas ◽  
Mitigation Strategies ◽  
System Structure ◽  
The Arctic ◽  
Risk Modeling ◽  
Wide Range ◽  
Adverse Weather ◽  
The Impact

Every aspect of human operations faces a wide range of risks, some of which can cause serious consequences. By the start of 21st century, mankind has recognized a new class of risks posed by climate change. It is obvious, that the global climate is changing, and will continue to change, in ways that affect the planning and day to day operations of businesses, government agencies and other organizations and institutions. The manifestations of climate change include but not limited to rising sea levels, increasing temperature, flooding, melting polar sea ice, adverse weather events (e.g. heatwaves, drought, and storms) and a rise in related problems (e.g. health and environmental). Assessing and managing climate risks represent one of the most challenging issues of today and for the future. The purpose of the risk modeling system discussed in this paper is to provide a framework and methodology to quantify risks caused by climate change, to facilitate estimates of the impact of climate change on various spheres of human activities and to compare eventual adaptation and risk mitigation strategies. The system integrates both physical climate system and economic models together with knowledge-based subsystem, which can help support proactive risk management. System structure and its main components are considered. Special attention is paid to climate risk assessment, management and hedging in the Arctic coastal areas.

Topics of Environmental Education Program in Coastal Areas

1992 ◽  
Vol 25 (9) ◽  
pp. 253-259 ◽  
Author(s):  
A. M. O. Rennhack ◽  
D. M. W. Zee ◽  
E. S. Cunha ◽  
M. F. Portilho
Keyword(s):  
Environmental Education ◽  
Rio De Janeiro ◽  
Local Community ◽  
Environmental Problems ◽  
Coastal Areas ◽  
State University ◽  
Urban Centers ◽  
Educational Support ◽  
Wide Range ◽  
Supply Information

Researches and Studies made by the Department of Oceanography of the Institute of Geoscience of the State University of Rio de Janeiro UERJ, evidenced the need for educational support where environment-related questions were concerned. A wide range of environment problems tend to concentrate in coastal areas, owing to disordinate urban growth combined with the lack of substructure to cope with it A large number of these problems can be minimized through the participation of the local community. Thus the goals of environmental education are to supply information, to promote a change in the population's attitude toward environmental problems, besides stimulating its participation by fostering its sense of responsibility. Preliminary results have demonstrated that the community has shown great interest in the work that has been proposed, and it has contributed with participation, promising response. Environmental education is fundamental when we consider possible solutions for environmental problems in coastal urban centers. Only by educating the main cause of environmental problems, man himself, will it be possible to consider the question starting from its very origin. This abstract presents two pioneer experiments in the Municipio of Rio de Janeiro, which are “Muito Prazer Marapendi” (“Glad to know you, Marapendi”) and “Troca de Areias da Praia de Copacabana” (“Exchange of Sands in Copacabana Beach”).

Home Learning in Times of COVID: Experiences of Parents

2020 ◽  
Vol 7 (1) ◽  
pp. 9 ◽  
Author(s):  
Shelina Bhamani ◽  
Areeba Zainab Makhdoom ◽  
Vardah Bharuchi ◽  
Nasreen Ali ◽  
Sidra Kaleem ◽  
...  
Keyword(s):  
Real Life ◽  
Sampling Technique ◽  
Online Classes ◽  
Google Docs ◽  
Learning Gap ◽  
Wide Range ◽  
Home Learning ◽  
Collection Data ◽  
Learning At Home ◽  
At Home

<p align="center"><em>The widespread prevalence of COVID-19 pandemic has affected academia and parents alike. Due to the sudden closure of schools, students are missing social interaction which is vital for better learning and grooming while most schools have started online classes. This has become a tough routine for the parents working online at home since they have to ensure their children’s education. The study presented was designed to explore the experiences of home learning in times of COVID-19. A descriptive qualitative study was planned to explore the experiences of parents about home learning and management during COVID-19 to get an insight into real-life experiences.  Purposive sampling technique was used for data collection.  Data were collected from 19 parents falling in the inclusion criteria. Considering the lockdown problem, the data were collected via Google docs form with open-ended questions related to COVID-19 and home learning. Three major themes emerged after the data analysis: impact of COVID on children learning; support given by schools; and strategies used by caregivers at home to support learning. It was analyzed that the entire nation and academicians around the world have come forward to support learning at home offering a wide range of free online avenues to support parents to facilitate home-learning. Furthermore, parents too have adapted quickly to address the learning gap that have emerged in their children’s learning in these challenging times. Measures should be adopted to provide essential learning skills to children at home. Centralized data dashboards and educational technology may be used to keep the students, parents and schools updated.</em></p>

scholarly journals A Systematic Review and Qualitative Synthesis Resulting in a Typology of Elementary Classroom Movement Integration Interventions

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Spyridoula Vazou ◽  
Collin A. Webster ◽  
Gregory Stewart ◽  
Priscila Candal ◽  
Cate A. Egan ◽  
...  
Keyword(s):  
Physical Activity ◽  
Teacher Collaboration ◽  
A Priori ◽  
Real Life ◽  
Dose Intensity ◽  
Routine Practice ◽  
Qualitative Synthesis ◽  
Wide Range ◽  
Meta Analyses ◽  
Movement Integration

Abstract Background/Objective Movement integration (MI) involves infusing physical activity into normal classroom time. A wide range of MI interventions have succeeded in increasing children’s participation in physical activity. However, no previous research has attempted to unpack the various MI intervention approaches. Therefore, this study aimed to systematically review, qualitatively analyze, and develop a typology of MI interventions conducted in primary/elementary school settings. Subjects/Methods Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to identify published MI interventions. Irrelevant records were removed first by title, then by abstract, and finally by full texts of articles, resulting in 72 studies being retained for qualitative analysis. A deductive approach, using previous MI research as an a priori analytic framework, alongside inductive techniques were used to analyze the data. Results Four types of MI interventions were identified and labeled based on their design: student-driven, teacher-driven, researcher-teacher collaboration, and researcher-driven. Each type was further refined based on the MI strategies (movement breaks, active lessons, other: opening activity, transitions, reward, awareness), the level of intrapersonal and institutional support (training, resources), and the delivery (dose, intensity, type, fidelity). Nearly half of the interventions were researcher-driven, which may undermine the sustainability of MI as a routine practice by teachers in schools. An imbalance is evident on the MI strategies, with transitions, opening and awareness activities, and rewards being limitedly studied. Delivery should be further examined with a strong focus on reporting fidelity. Conclusions There are distinct approaches that are most often employed to promote the use of MI and these approaches may often lack a minimum standard for reporting MI intervention details. This typology may be useful to effectively translate the evidence into practice in real-life settings to better understand and study MI interventions.

scholarly journals Analytical mathematical schemes: Circular rod grounded via transverse Poisson’s effect and extensive wave propagation on the surface of water

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 545-554
Author(s):  
Asghar Ali ◽  
Aly R. Seadawy ◽  
Dumitru Baleanu
Keyword(s):  
Wave Propagation ◽  
Partial Differential Equations ◽  
Differential Equations ◽  
Longitudinal Wave ◽  
Symbolic Computation ◽  
Boussinesq Equation ◽  
Nonlinear Partial Differential Equations ◽  
Wave Model ◽  
Simple Equation ◽  
Partial Differential

AbstractThis article scrutinizes the efficacy of analytical mathematical schemes, improved simple equation and exp(-\text{&#x03A8;}(\xi ))-expansion techniques for solving the well-known nonlinear partial differential equations. A longitudinal wave model is used for the description of the dispersion in the circular rod grounded via transverse Poisson’s effect; similarly, the Boussinesq equation is used for extensive wave propagation on the surface of water. Many other such types of equations are also solved with these techniques. Hence, our methods appear easier and faster via symbolic computation.

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