scholarly journals PHYSICAL MODELLING OF BEACH EROSION AND LITTORAL DRIFT

1988 ◽  
Vol 1 (21) ◽  
pp. 134 ◽  
Author(s):  
Otavio J. Sayao ◽  
Robert B. Nairn
Keyword(s):  
Grain Size ◽  
Physical Model ◽  
Scale Effects ◽  
Physical Modelling ◽  
Beach Erosion ◽  
Model Design ◽  
Littoral Drift ◽  
Sedimentary Processes ◽  
Dynamic Similarity ◽  
Proposed Model

A new procedure for physical modelling of beach sedimentary processes is presented. It is shown that the modelling requirements proposed by Dean (1985) are necessary but not sufficient for dynamic similarity. Quantification of scale effects due to slope and relative grain size scaling conditions enables extrapolation of the physical model results to prototype situations. Selected examples of the application of the proposed model design are also given.

scholarly journals Towards Recognition of Scale Effects in a Solid Model of Lattices with Tensegrity-Inspired Microstructure

Solids ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 50-59
Author(s):  
Wojciech Gilewski ◽  
Anna Al Sabouni-Zawadzka
Keyword(s):  
Mechanical Properties ◽  
Continuum Model ◽  
Scale Effects ◽  
Theory Of Elasticity ◽  
Solid Model ◽  
Gradient Theory ◽  
General Description ◽  
Normal Forces ◽  
Second Gradient ◽  
Proposed Model

This paper is dedicated to the extended solid (continuum) model of tensegrity structures or lattices. Tensegrity is defined as a pin-joined truss structure with an infinitesimal mechanism stabilized by a set of self-equilibrated normal forces. The proposed model is inspired by the continuum model that matches the first gradient theory of elasticity. The extension leads to the second- or higher-order gradient formulation. General description is supplemented with examples in 2D and 3D spaces. A detailed form of material coefficients related to the first and second deformation gradients is presented. Substitute mechanical properties of the lattice are dependent on the cable-to-strut stiffness ratio and self-stress. Scale effect as well as coupling of the first and second gradient terms are identified. The extended solid model can be used for the evaluation of unusual mechanical properties of tensegrity lattices.

scholarly journals Physical Modelling of Tundish Slag Entrainment under Various Technological Conditions

2017 ◽  
Vol 62 (3) ◽  
pp. 1467-1471 ◽  
Author(s):  
K. Michalek ◽  
K. Gryc ◽  
L. Socha ◽  
M. Tkadlečková ◽  
M. Saternus ◽  
...  
Keyword(s):  
Physical Model ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Physical Modelling ◽  
Critical Periods ◽  
Operational Conditions ◽  
Modelling Methodology ◽  
Slag Entrainment ◽  
The Individual

AbstractThis paper deals with the issue of physical modelling of vortexes creation and tundish slag entrainment over the mouth of the nozzle into the individual casting strands. Proper physical model is equivalent to the operational continuous casting machine No. 2 in TŘINECKÉ ŽELEZÁRNY, a.s. Physical modelling methodology and simulated operational conditions are shortly described. Physical modelling was used for the evaluation of current conditions of steel casting at the application of different impact pads in the tundish. Further, laboratory measurement on the physical model aiming the determination of exact critical periods of vortexes creation and study of the slag entrainment as a consequence of changes in surface level during the tundish refilling to standard level were realised. The obtained results were analysed and discussed.

scholarly journals Scale effects in physical modelling of a generalized OWC

2018 ◽  
Vol 162 ◽  
pp. 248-258 ◽  
Author(s):  
Antonino Viviano ◽  
Stefania Naty ◽  
Enrico Foti
Keyword(s):  
Scale Effects ◽  
Physical Modelling

scholarly journals The relevance of larval biology on spatiotemporal patterns of pathogen connectivity among open-marine salmon farms

2020 ◽  
Vol 77 (3) ◽  
pp. 505-519 ◽  
Author(s):  
Danielle Cantrell ◽  
Ramón Filgueira ◽  
Crawford W. Revie ◽  
Erin E. Rees ◽  
Raphael Vanderstichel ◽  
...  
Keyword(s):  
Physical Model ◽  
Temporal Variability ◽  
Management Strategies ◽  
Physical Modelling ◽  
Sea Lice ◽  
Dispersal Patterns ◽  
Larval Biology ◽  
Survival And Development ◽  
Spring Freshet ◽  
Additive Modeling

Warming waters are changing marine pathogen dispersal patterns and infectivity worldwide. Coupled biological–physical modelling has been used in many systems to determine the connectivity of metapopulations via infectious disease particles. Here we model the connectivity of sea lice larvae (Lepeophtheirus salmonis) among salmon farms in the Broughton Archipelago, British Columbia, Canada, using a coupled biological–physical model. The physical model simulated pathogen dispersal, while the biological component influenced the survival and developmental rates of the sea lice. Model results predicted high temporal variability in connectivity strength among farms, an emergent effect from the interacting parts of the simulation (dispersion versus survival and development). Drivers of temporal variability were disentangled using generalized additive modeling, which revealed the variability was most strongly impacted by the spring freshet, which can act as a natural aid for sea lice control in the Broughton Archipelago. Our results suggest that farm management strategies can benefit by accounting for short-term spikes in regional pathogen connectivity among farms. Additionally, future scenarios of a warming climate with reduced snowpack can make sea lice control more challenging.

scholarly journals WAVE OVERTOPPIMG EQUATION

1976 ◽  
Vol 1 (15) ◽  
pp. 156 ◽  
Author(s):  
J. Richard Weggel
Keyword(s):  
Scale Effects ◽  
Beach Erosion ◽  
Scale Model ◽  
Lake Okeechobee ◽  
Wave Runup ◽  
Large Wave ◽  
Engineering Research ◽  
Test Conditions ◽  
Model Wave ◽  
Wave Heights

In the early 1950's the Corps of Engineers' Jacksonville District initiated a series of laboratory tests to investigate the overtopping of proposed levee sections for Lake Okeechobee, Florida. For economic reasons, the alternative to build levees with crest elevations that were at times below the limit of wave runup was investigated and the quantities of water carried over the structures for various freeboard allowances, structure slopes and wave conditions determined. The initial tests were conducted at the Waterways Experiment Station (WES) in Vieksburg, Mississippi for the Jacksonville District at what was taken to be a 1 to 30 model scale. Model wave heights varied from 1+.05 cm to 12.2 cm (0.133 to 0.^0 ft). In order to expand the range of test conditions investigated, the Beach Erosion Board, currently the Coastal Engineering Research Center (CERC), commissioned an expanded series of tests that considered the overtopping of riprap faced, curved and stepped seawalls as well as the overtopping of "smooth" slopes. These tests, also conducted at WES, were considered to be at a 1 to 17 scale with model wave heights ranging from 5-36 cm to 21.5 cm (0.176 to O.706 ft). A number of tests were subsequently conducted in CERC's large wave tank to determine the influence scale effects might have on overtopping. These tests are referred to as 1 to 2 1/2 scale tests. The model wave heights investigated ranged from U8.8 cm to 11*0.2 cm. (1.60 to h.6o ft).

scholarly journals Statistical Analysis of Grain-Scale Effects of Twinning Deformation for Magnesium Alloys under Cyclic Strain Loading

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2454
Author(s):  
Damin Lu ◽  
Shuai Wang ◽  
Yongting Lan ◽  
Keshi Zhang ◽  
Wujun Li ◽  
...  
Keyword(s):  
Grain Size ◽  
Statistical Analysis ◽  
Magnesium Alloys ◽  
Probability Function ◽  
Volume Fraction ◽  
Scale Effects ◽  
Low Cycle Fatigue ◽  
Cyclic Strain ◽  
Statistical Distribution ◽  
Twin Thickness

To reveal the relationship between grain size and twinning deformation of magnesium alloys under cyclic strain, this study carried out a group of strain-controlled low-cycle fatigue experiments and statistical analysis of microstructures. Experimental results show that the shape of the hysteresis loop exhibits significant asymmetry at different strain amplitudes, and the accumulation of residual twins plays an important role in subsequent cyclic deformation. For the different strain amplitudes, the statistical distribution of the grain size of magnesium alloy approximately follows the Weibull probability function distribution, while the statistical distribution of twin thickness is closer to that of Gaussian probability function. The twin nucleation number (TNN) increases with the increase of grain size, but there is no obvious function relationship between twin thickness and grain size. Twin volume fraction (TVF) increases with the increase of grain size, which is mainly due to the increase of TNN. This work can provide experimental evidence for a more accurate description of the twinning deformation mechanism.

A Methodology for the Analysis of Physical Model Scale Effects on the Simulation of Wave Propagation up to Wave Breaking: Preliminary Physical Model Results

2008 ◽  
Author(s):  
Conceic¸a˜o Fortes ◽  
Maria da Grac¸a Neves ◽  
Joa˜o Alfredo Santos ◽  
Rui Capita˜o ◽  
Artur Palha ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Physical Model ◽  
Scale Effects ◽  
National Laboratory ◽  
Physical Models ◽  
Type Model ◽  
Research Activity ◽  
Joint Research ◽  
Common Structure ◽  
Constant Slope

This paper describes the experiments performed at the National Laboratory for Civil Engineering (LNEC) aiming at simulating, in a flume, the wave propagation along a constant slope bottom that ends on a sea wall coastal defence structure, a common structure employed in the Portuguese coast. The objective of these tests is to calibrate the parameters of FUNWAVE, a Boussinesq type model, for wave propagation in coastal regions. This is the first step in the validation of a methodology to combine numerical and physical models in the study of the interactions between beaches and structures. This work is performed in the framework of the Composite Modelling of the Interactions between Beaches and Structures (CoMIBBs) project, a joint research activity of the HYDRALAB III European project.

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