scholarly journals Numerical simulation of the movement behavior of floating structures

2021 ◽  
pp. 55-62
Author(s):  
Wolfgang Schmidt ◽  
Peter Strangfeld ◽  
Eduard Volker ◽  
Yaraslau Sliavin
Keyword(s):  
Water Waves ◽  
Energy Use ◽  
Field Studies ◽  
Hydraulic Testing ◽  
Movement Behavior ◽  
Open Pit ◽  
Wave Forces ◽  
Floating Platform ◽  
Ansys Fluent ◽  
Effect Of Water

The sea level is rising, and floods threaten the infrastructure all over the world; therefore, we should identify the risks for envelops of buildings and settlements. The risks arise due to the new boundary conditions and a direct contact between the water flows in motion. A floating construction site requires a manifold adaptation of structures. The paper demonstrates the effect of water waves on floating houses built on abandoned open pit mines. Pictures of destroyed accessways to such properties have proven the need to study the effect of water waves on floating houses. In order to minimize the time and spending on experimental activities, some of the field studies should be replaced by numerical simulations using modern computing equipment and ANSYS FLUENT, ANSYS MECHANICAL FSI, and ANSYS AQWA software. The results can be validated using a hydraulic testing channel (15 x 5 m), a floating platform near the harbor of Lake Gro r schener See and floating houses in the Lusatian Lakeland. The results demonstrate the wave forces acting on the structures of the pontoons. New connection elements, adapted versions of materials and structures have been developed, water waves are damped, and options for the wave energy use have been analyzed.

ESTIMATION OF PECULIARITIES OF TEMPERATURE INVERSION FORMATION IN OPEN MINING IN THE ARCTIC CONDITIONS

2021 ◽  
Vol 4 (1) ◽  
pp. 59-75
Author(s):  
S.G. Gendler ◽  
◽  
I.A. Borisovskiy ◽  
Keyword(s):  
Temperature Inversion ◽  
Open Pit ◽  
The Arctic ◽  
Effect Of Temperature ◽  
Ansys Fluent ◽  
Air Masses ◽  
Steady State Temperature ◽  
Arctic Conditions ◽  
Air Layers ◽  
Fluent Software

The article presents the results of studies on the study of the effect of temperature in-versions on the efficiency of ventilation of a quarry space. It was found that a negative tem-perature difference leads to cooling of the surface air layers, which can cause the accumula-tion of cooled air masses in the lower part of the open pit and a decrease in the intensity of air exchange. It is shown that the assessment of the peculiarities of the formation of the pa-rameters of the mine atmosphere and the substantiation of the boundaries of the use of natu-ral ventilation of gold-ore quarries, taking into account the steady-state temperature gradi-ent, can be carried out using mathematical modeling based on the Ansys Fluent software package.

scholarly journals Wave interaction with Floating platform of different shapes and supports using BEM approach

2017 ◽  
Vol 14 (2) ◽  
pp. 115-133
Author(s):  
Anoop I. Shirkol ◽  
Nasar Thuvanismail
Keyword(s):  
Numerical Model ◽  
Elastic Plate ◽  
Wave Interaction ◽  
Wave Force ◽  
Ocean Waves ◽  
Wave Forces ◽  
Thin Elastic Plate ◽  
Floating Platform ◽  
Floating Elastic Plate ◽  
Different Shapes

Wave interaction with a floating thin elastic plate which can be used as floating platform is analyzed using Boundary Element Method (BEM) for different shapes such as rectangular, circular and triangular. Different support conditions are considered and the performance of the floating platform under the action of ocean waves is explored. The study is performed under the assumption of linearized water wave theory and the floating elastic plate is modelled based on the Euler-Bernoulli beam theory. Using Galerkin’s approach, a numerical model has been developed and the hydrodynamic loading on the floating elastic plate of shallow draft (thickness) is investigated. The wave forces are generated by the numerical model for the analysis of the floating plate. The resulting bending moment and optimal deflection due to encountering wave force is analysed. The present study will be helpful in design and analysis of the large floating platform in ocean waves.

Manoeuvring Study of a Container Ship in Shallow Water Waves

2018 ◽  
Author(s):  
Manases Tello Ruiz ◽  
Marc Mansuy ◽  
Guillaume Delefortrie ◽  
Marc Vantorre
Keyword(s):  
Shallow Water ◽  
Water Waves ◽  
Numerical Study ◽  
Scale Model ◽  
Wave Forces ◽  
Shallow Water Waves ◽  
The North ◽  
Captive Model Tests ◽  
Calm Water ◽  
Large Container

When approaching or leaving a port a ship often needs to perform manoeuvres in the presence of waves. At the same time the water depth is still limited for deep drafted vessels. For manoeuvring simulation purposes this requires a manoeuvring model which includes phenomena such as short crested waves and squat effects. The present paper addresses the manoeuvring problem in shallow water waves numerically and experimentally. The numerical study is conducted by means of potential theory, incorporating first and second order exciting wave forces, and their superposition to the calm water manoeuvring models. The applicability of such an approach is also investigated. The experimental work has been conducted at Flanders Hydraulics Research (in cooperation with Ghent University) with a scale model of an ultra large container vessel. Captive model tests comprise harmonic yaw tests and steady straight line tests with and without waves, at different forward speeds, wave frequencies and amplitudes, in head and following waves. Waves are chosen to represent conditions commonly met by ships in the Belgian coastal zone of the North Sea.

Gap Resonance of Fixed Floating Multi Caissons

2019 ◽  
Author(s):  
Limin Chen ◽  
Guanghua He ◽  
Harry B. Bingham ◽  
Yanlin Shao
Keyword(s):  
Free Surface ◽  
Water Waves ◽  
Offshore Structures ◽  
Wave Number ◽  
Wave Forces ◽  
Wave Runup ◽  
Floating Bodies ◽  
Constrained Interpolation ◽  
Gap Resonance ◽  
Narrow Gaps

Abstract Generally, numerous marine and offshore structures are composed of a number of modules which introduce narrow gaps between the multi-modules arranged side by side. The interaction between water waves and floating structures excites complex wave runup in the gaps and wave forces on the adjacent modules. In this study, free surface oscillations in twin narrow gaps between identical floating rectangular boxes are investigated by establishing a 2D viscous flow numerical wave tank based on a Constrained Interpolation Profile (CIP) method. The Tangent of Hyperbola for INterface Capturing (THINC) method is employed to capture the free surface. The rigid floating bodies are treated by a Virtual Particle Method (VPM). The incident waves are generated by an internal wave maker. For the fixed module cases, the computational results of wave height in narrow gaps are found in good coincidence with the available experimental measurements, especially for the resonant frequencies. The wave forces on the floating bodies are calculated numerically. The characteristic response of wave forces on the leading and rear bodies are consistent with the free surface elevations in the corresponding narrow gaps. With shallow draft, the gap resonance occurs at higher wave number.

scholarly journals Genetic structure of a Virginia opossum (Didelphis virginiana) population inhabiting a fragmented agricultural ecosystem

2012 ◽  
Vol 90 (1) ◽  
pp. 101-109 ◽  
Author(s):  
William S. Beatty ◽  
James C. Beasley ◽  
Guha Dharmarajan ◽  
Olin E. Rhodes
Keyword(s):  
Genetic Structure ◽  
Field Studies ◽  
Didelphis Virginiana ◽  
Movement Behavior ◽  
Pairwise Comparisons ◽  
Genetic Composition ◽  
Agricultural Ecosystem ◽  
Habitat Patches ◽  
Virginia Opossum

Fragmentation has drastically altered the quality of habitats throughout numerous ecosystems, often leading to dramatic changes in the composition of wildlife communities. The ecology and associated movement behavior of a species may also be modified as a result of forest fragmentation, resulting in changes in genetic composition of the affected species. In this research, we evaluated the genetic structure of the Virginia opossum ( Didelphis virginiana Kerr, 1792) at the landscape and local scales in a fragmented, agricultural ecosystem in northern Indiana using 13 microsatellite loci. We examined 290 samples from opossums inhabiting 28 discrete habitat patches, and evaluated partitioning of genetic variation of opossums among and within habitat patches. We observed low but significant levels of genetic structure (FST = 0.005) overall, and pairwise comparisons of FST values among habitat patches also were relatively low. Relatedness within patches was highly variable (–0.077 ≤ rxy ≤ 0.060), with a few patches exhibiting significantly higher levels of relatedness than random expectations, and we detected no evidence of sex-biased natal dispersal. These results contrast with previous field studies that documented male-biased dispersal in the Virginia opossum, indicating dispersal in this species is plastic and dependent upon local environmental conditions.

scholarly journals IMPACT WAVE FORCES ON VERTICAL AND HORIZONTAL PLATE

1978 ◽  
Vol 1 (16) ◽  
pp. 141
Author(s):  
S.R. Massel ◽  
M. Oleszkiewicz ◽  
W. Trapp
Keyword(s):  
Water Waves ◽  
Difficult Problem ◽  
Wave Forces ◽  
Horizontal Plate ◽  
Hydrodynamic Impact ◽  
Impact Forces ◽  
Wave Parameters ◽  
The Subject ◽  
The Impact ◽  
Impact Problem

The hydrodynamic impact problem is a very difficult problem because the physics of what actually happens during the instant of impact are not understood. Despite of fact that a large number of references exist on the subject, many questions are left unanswered. The object of this research is to investigate the problems of hydrodynamic impact associated with the water waves impacting on the vertical and horizontal plates..Of particular interest are the impact forces, their relation to the incident wave parameters and scale effect problems.

scholarly journals Sarcoglottis neillii (Orchidaceae: Spiranthinae), a new species from the Andean Tepui Region of Ecuador and Peru

Phytotaxa ◽  
2019 ◽  
Vol 427 (1) ◽  
pp. 1-8
Author(s):  
GERARDO A. SALAZAR ◽  
FRANCISCO TOBAR ◽  
ROLANDO JIMÉNEZ-MACHORRO ◽  
EFRAÍN FREIRE ◽  
MARCIA PEÑAFIEL CEVALLOS
Keyword(s):  
National Park ◽  
Conservation Status ◽  
Field Studies ◽  
Open Pit ◽  
Open Pit Mining ◽  
Preliminary Assessment ◽  
Unknown Species ◽  
Leaf Coloration ◽  
Data Deficient ◽  
A New Species

Recent exploration of the foothills of the Cordillera del Cóndor, southeastern Ecuador, led to the discovery of an unknown species of Sarcoglottis, and subsequent study in Peruvian herbaria permitted to record it in Peru. Here we describe it as Sarcoglottis neillii and provide a detailed drawing and color photographs taken from live plants. We compare its morphology with that of similar members of Sarcoglottis and conduct a preliminary assessment of its conservation status. Sarcoglottis neillii belongs to a small group of species including S. metallica, S. maroaënsis and S. stergiosii, differing from the former two species in leaf coloration and from the latter in flower size and labellum morphology. The single known Ecuadorian location of S. neillii was destroyed by extensive open pit-mining activities, but the several records from Peru suggest that the species is widespread; three locations occur within the Yanachaga-Chemillén National Park, but information on its actual range and potential threats is lacking and we suggest for it the category of Data Deficient (DD) until further field studies permit a better-informed assessment of its risk status.

scholarly journals Effect of water velocity and temperature on energy use, behaviour and mortality of pallid sturgeon Scaphirhynchus albus larvae

2020 ◽  
Vol 97 (6) ◽  
pp. 1690-1700
Author(s):  
Joseph T. Mrnak ◽  
Laura B. Heironimus ◽  
Daniel A. James ◽  
Steven R. Chipps
Keyword(s):  
Energy Use ◽  
Water Velocity ◽  
Effect Of Water ◽  
Pallid Sturgeon ◽  
Scaphirhynchus Albus

Dispersion of Particles Coming Out of the Mouth While Speaking in a Ventilated Indoor Environment

2021 ◽  
Author(s):  
Morteza Ali Masoomi ◽  
Mazyar Salmanzadeh ◽  
Goodarz Ahmadi
Keyword(s):  
Coming Out ◽  
Indoor Environment ◽  
Distribution Systems ◽  
Ventilation System ◽  
Field Studies ◽  
Continuous Phase ◽  
Ansys Fluent ◽  
Air Mixing ◽  
Long Time ◽  
Discrete Phase

Abstract Breathing air that contains virus-infected droplets is the leading cause of Covid-19 transmission. Sneezing, coughing, breathing, and talking of an infected person would generate aerosolized droplets that carry the coronavirus. Earlier research efforts have focused on sneezing and coughing as the primary transmission sources. New experiments and field studies have shown that breathing and talking are also effective mechanisms in spreading viruses. In this article, the dispersion of particles/droplets during speaking is studied. COVID-19 virus is about 120 nanometers and is suspended in saliva or mucus droplets emitted by an injected person. These droplets evaporate in a fraction of a second as they enter the environment and reduce in size. However, the droplets’ viral content remains the same as they move by the room’s airflow. The particles from sneezing and coughing are larger than those released by speaking. As the particles/droplets are small, the effect of gravity is small, and they remain suspended in the air for a long time. Also, being small makes them more easily penetrate the respiratory passages. Using the computational fluid dynamics method in conjunction with the ANSYS-Fluent software, the particle transport and dispersion were simulated. The Eulerian approach modeled the airflow (continuous phase), and the Lagrangian approach modeled the particle (discrete phase) movements. This study also investigated the ventilation system’s effects on the distribution of particles in the indoor environment. The displacement and mixing air distribution systems were considered. Simulation results showed that droplets remain suspended in the room for a relatively long time after evaporation. Large particles were deposited quickly, and a significant percentage of smaller particles were removed by the ventilation system. The concentration of particles in the upper half of the room was also quite low for the mixing ventilation system. This was due to the fact that the room air mixing system is relatively uniform; this uniformity of airflow caused the particles to get trapped quickly. Also, for the displacement system, the room airflow was not uniform; these particles were then dispersed in the room and spent more time in the indoor environment.

The effect of water stress on the energy use and growth of Cassia bicapsularis

2020 ◽  
pp. 73-82
Author(s):  
F.Y. Liao ◽  
Y.F. Wen ◽  
C.F. Huang ◽  
S.Y. Shen ◽  
L.Q. Yang
Keyword(s):  
Water Stress ◽  
Energy Use ◽  
Effect Of Water
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