Three‐Dimensional Physical Modelling of Tsunamis Generated by Partially Submerged Landslides

2022 ◽  
Author(s):  
Tomoyuki Takabatake ◽  
Dawn Chenxi Han ◽  
Justin Joseph Valdez ◽  
Naoto Inagaki ◽  
Martin Mäll ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Physical Modelling

Wave-in-Deck Loads for an Intricate Pile-Supported Pier and Variation With Deck Clearance

2013 ◽  
Author(s):  
Andrew Cornett ◽  
David Anglin ◽  
Trevor Elliott
Keyword(s):  
Water Waves ◽  
Three Dimensional ◽  
Wave Structure ◽  
Physical Modelling ◽  
Interaction Process ◽  
Air Gap ◽  
Scale Model ◽  
Shallow Water Waves ◽  
Structure Interaction ◽  
Wave Structure Interaction

Many deck structures are located at elevations low enough to be impacted by large waves. However, due to the highly complex and impulsive nature of the interactions between wave crests and intricate deck structures, establishing reliable estimates of extreme pressures and forces for use in design remains challenging. In this paper, results from an extensive set of three-dimensional scale model tests conducted to support the design of a large pile-supported pier (or jetty) are presented and discussed. Relationships between maximum wave-in-deck loads and the deck clearance (air gap) are presented and discussed. Results from numerical simulations of the wave-structure interaction process obtained using the three-dimensional CFD software FLOW-3D® are also presented and discussed. Finally, some initial comparisons between the numerical and physical modelling are also included. This paper provides new insights concerning the character and magnitude of the hydrodynamic pressures and loads exerted on intricate pile-supported deck structures due to impact by non-linear shallow-water waves, and the relationships between the hydrodynamic forcing and the deck clearance or air gap.

NON-CARTESIAN, TOPOGRAPHY-BASED AVALANCHE EQUATIONS AND APPROXIMATIONS OF GRAVITY DRIVEN FLOWS OF IDEAL AND VISCOUS FLUIDS

2009 ◽  
Vol 19 (01) ◽  
pp. 127-171 ◽  
Author(s):  
I. LUCA ◽  
Y. C. TAI ◽  
C. Y. KUO
Keyword(s):  
Thin Layer ◽  
Three Dimensional ◽  
Physical Modelling ◽  
Viscous Fluids ◽  
Curvilinear Coordinates ◽  
Governing Equations ◽  
Tensor Fields ◽  
Full Generality ◽  
Gravity Driven ◽  
Arbitrary Topography

When dealing with geophysical flows across three-dimensional topography or other thin layer flows, for the physical modelling and for computational reasons, it is more convenient to use curvilinear coordinates adapted to the basal solid surface, instead of the Cartesian coordinates. Using such curvilinear coordinates, e.g. introduced by Bouchut and Westdickenberg,3 and the corresponding contravariant components of vector and tensor fields, we derive in full generality the governing equations for the avalanche mass. These are next used to deduce (i) the thin layer equations for arbitrary topography, when the flowing mass is an ideal fluid, and (ii) the thin layer equations corresponding to arbitrary topography and to a viscous fluid that experiences bottom friction, modelled by a viscous sliding law.

scholarly journals Physical modelling of the interaction between powder avalanches and defence structures

2002 ◽  
Vol 2 (3/4) ◽  
pp. 193-202 ◽  
Author(s):  
F. Naaim-Bouvet ◽  
M. Naaim ◽  
M. Bacher ◽  
L. Heiligenstein
Keyword(s):  
Vertical Velocity ◽  
Three Dimensional ◽  
Physical Modelling ◽  
Front Velocity ◽  
Small Scale ◽  
Water Tank ◽  
A Value ◽  
Physical Experiments ◽  
Scale Models ◽  
Increasing Function

Abstract. In order to better understand the interaction between powder snow avalanches and defence structures, we carried out physical experiments on small-scale models. The powder snow avalanche was simulated by a heavy salt solution in a water tank. Quasi two-dimensional and three-dimensional experiments were carried out with different catching dam heights. For the reference avalanche, the velocity just behind the nose in the head was greater than the front velocity. For the 2-D configuration, the ratio Umax/Ufront was as high as 1.6, but it depends on the height. For the 3-D configuration, this ratio differed slightly and was even greater (up to 1.8). The vertical velocity rose to 106% of the front velocity for the 3-D simulation and 74% for the 2-D simulation. The reduction in front velocity due to the presence of dams was an increasing function of the dam height. But this reduction depended on topography: dams were more effective on an open slope avalanche (3-D configuration). The ratio Umax/Ufront was an increasing function of the dam’s height and reached a value of 1.9. The obstacle led to a reduction in vertical velocity downstream of the vortex zone.

THE SEISMIC EXPRESSION OF THREE-DIMENSIONAL SANDBOX MODELS

1996 ◽  
Vol 36 (1) ◽  
pp. 490
Author(s):  
D.H. Sherlock ◽  
B.J. Evans ◽  
C.C. Ford
Keyword(s):  
Seismic Data ◽  
Seismic Waves ◽  
Three Dimensional ◽  
Physical Modelling ◽  
Seismic Wave Propagation ◽  
Construction Time ◽  
Geological Structures ◽  
Seismic Modelling ◽  
Solid Models ◽  
First Time

Analogue sandbox models provide cheap, concise data and allow the evolution of geological structures to be observed under controlled conditions in a laboratory. Seismic physical modelling is used to study the effects of seismic wave propagation in isotropic and anisotropic media and to improve methods of data acquisition, processing and interpretation. These two independent geological modelling techniques have been linked for the first time, to combine and expand the existing benefits of each method.Seismic physical modelling to date has employed solid models, constructed with pre-determined structures built into the model. Previous attempts to adapt this technology to unconsolidated materials failed due to the severe energy attenuation of seismic waves in cohesionless grain matrices, and excessive signal scatter due to scaling limitations of the geological feature size to wavelength ratio. This paper presents our research to overcome these problems and thereby allow the successful seismic imaging of sandbox models.A number of techniques have been developed to combine these two independent modelling methods and results show that it is possible to image several layers within the models, demonstrating the potential to interpret complex geological structures within such models. For seismic modelling, the main advantages are that the seismic data collected from these models contain natural variation that cannot be built into solid models, which results in a more realistic image, and the cost and construction time of the models are also dramatically reduced. For sandbox modelling, the recording of seismic data over them allows far more detailed interpretation of the structures than previously possible and also allows direct comparison with field data for the first time, to substantiate or negate an existing interpretation.

Experimental technique for visualization of aquitard compaction over aquifer caused by excess pumping

2020 ◽  
Author(s):  
Kazunori Tabe ◽  
Masaatsu Aichi
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Three Dimensional ◽  
Physical Modelling ◽  
Pumping Test ◽  
Silica Sand ◽  
Clay Layer ◽  
Synthetic Clay ◽  
Transparent Soils

<p> Transparent soils are developed as a physical modelling of macroscopic soil behaviors in geotechnical engineering aspect. Transparent surrogates with its index-matching fluid, called as transparent porous media or transparent soils, have been used for simulating geotechnical properties of natural soils. Visualization technique itself have been applied to microscopic level of soil deformation and soil flow problems such as X-ray, Computerized Tomography (CT), and Magnetic Resonance Imaging (MRI) cameras by very expensive apparatuses with highly operating skills. Geotechnical researches need rather understanding of macroscopic scale of larger test models with inexpensive experimental industrial substances. Transparent soils have been developed to achieve these needs with easy handling performance. <br> The authors demonstrated a pumping test in a glass tank of 30mm width by 80mm length by 70mm height filled with transparent hydrated superabsorbent polymer to represent aquitard (clay layer) over aquifer (saturated silica sand). The subsidence within the synthetic clay layer due to pumping of pore water from silica sand was constantly monitored by target racking method using four 8mm-diameter particles immersed in the synthetic clay layer. The test successfully visualized deformation due to vertical propagation of pore water pressure during subsidence event within the transparent synthetic clay layer. It was also found that this experiment result and the results from three-dimensional numerical simulation of poroelastic deformation were consistent with each other.</p>

On the role and challenges of CFD in the aerospace industry

2016 ◽  
Vol 120 (1223) ◽  
pp. 209-232 ◽  
Author(s):  
P. R. Spalart ◽  
V. Venkatakrishnan
Keyword(s):  
User Interfaces ◽  
Three Dimensional ◽  
Physical Modelling ◽  
Design Flow ◽  
Navier Stokes ◽  
Solution Quality ◽  
Substantial Impact ◽  
Computing Power ◽  
Eddy Simulation ◽  
Aerospace Applications

ABSTRACTThis article examines the increasingly crucial role played by Computational Fluid Dynamics (CFD) in the analysis, design, certification, and support of aerospace products. The status of CFD is described, and we identify opportunities for CFD to have a more substantial impact. The challenges facing CFD are also discussed, primarily in terms of numerical solution, computing power, and physical modelling. We believe the community must find a balance between enthusiasm and rigor. Besides becoming faster and more affordable by exploiting higher computing power, CFD needs to become more reliable, more reproducible across users, and better understood and integrated with other disciplines and engineering processes. Uncertainty quantification is universally considered as a major goal, but will be slow to take hold. The prospects are good for steady problems with Reynolds-Averaged Navier-Stokes (RANS) turbulence modelling to be solved accurately and without user intervention within a decade – even for very complex geometries, provided technologies, such as solution adaptation are matured for large three-dimensional problems. On the other hand, current projections for supercomputers show a future rate of growth only half of the rate enjoyed from the 1990s to 2013; true exaflop performance is not close. This will delay pure Large-Eddy Simulation (LES) for aerospace applications with their high Reynolds numbers, but hybrid RANS-LES approaches have great potential. Our expectations for a breakthrough in turbulence, whether within traditional modelling or LES, are low and as a result off-design flow physics including separation will continue to pose a substantial challenge, as will laminar-turbulent transition. We also advocate for much improved user interfaces, providing instant access to rich numerical and physical information as well as warnings over solution quality, and thus naturally training the user.

Effect of driver and road characteristics on required preview sight distance

2002 ◽  
Vol 29 (2) ◽  
pp. 276-288 ◽  
Author(s):  
Yasser Hassan ◽  
Tarek Sayed
Keyword(s):  
Computer Animation ◽  
Linear Regression Analysis ◽  
Three Dimensional ◽  
Human Perception ◽  
Physical Modelling ◽  
Geometric Design ◽  
Geometric Parameters ◽  
Horizontal Curve ◽  
Sight Distance ◽  
Road Characteristics

Highway geometric design is a complex process that is closely related to human perception and behaviour. Among the human perception issues that can affect highway geometric design is the preview sight distance, which has been defined as the distance required to perceive a horizontal curve and react properly to it. Previous attempts to quantify preview sight distance included measurement on actual roads, physical modelling, and computer animation. This paper presents a computer animation experiment that was designed to examine the effects of geometric parameters and driver characteristics on preview sight distance and to statistically model preview sight distance. Statistical analysis showed that preview sight distance depends on geometric parameters such as the horizontal curve radius, use of spiral curve and its length, presence of crest vertical curve, algebraic difference of vertical grades, vertical curvature, and road delineation. On the other hand, driver characteristics were mostly found to be insignificant parameters. Finally, statistical models were developed to predict the value of preview sight distance using linear regression analysis. The models vary in simplicity and accuracy and were formulated as a function of the general alignment configuration or as a function of the exact geometric parameters.Key words: highway geometric design, sight distance, driver characteristics, three-dimensional alignment.

A COMPARISON OF PHYSICAL MODEL WITH FIELD DATA OVER OLIVER FIELD, VULCAN GRABEN

1995 ◽  
Vol 35 (1) ◽  
pp. 26 ◽  
Author(s):  
B.J. Evans ◽  
B.F. Oke ◽  
M. Urosevic ◽  
K. Chakraborty
Keyword(s):  
Physical Model ◽  
Seismic Data ◽  
Field Data ◽  
Joint Venture ◽  
Survey Design ◽  
Three Dimensional ◽  
Physical Modelling ◽  
Field Work ◽  
Physical Models ◽  
2D And 3D

Physical models representing the three dimensional geology of oil fields can be built from materials such as plastics and resins. Using ultrasound transmitters and receivers, 2D and 3D seismic surveys can be simulated to aid in the survey design of field work, provide insight into data processing, and can test interpretation concepts. Such modelling simulates most aspects of both land and marine seismic.In 1993 BHP Petroleum, on behalf of the AC/P6 Joint Venture, contracted Curtin University's Geophysics Group to build a 1:40,000 scale, 11-layer, 2.5D model of the Oliver Field so that 2D and 3D field data acquisition and processing could be simulated. A 2.5D model is invariant in the strike direction, but can answer most of the questions of a true 3D model at a fraction of the effort and cost. This was the first such model built in Australia, and one of the most complex physical models ever built.Of interest was the quality of imaging under the fault shadow near reservoir level, and whether the application of dip or strike 3D acquisition and processing approaches could improve the seismic data quality. Consequently, both dip (2D) and strike (2.5D) seismic data were acquired over the model using similar parameters to those used in conventional offshore acquisition. The data were processed to migration stage and compared with the field seismic data. Numerical model and field VSP data were also processed and compared with the field and physical model seismic data.The good agreement between processed physical model seismic and field seismic shows that physical modelling of geology has application in both two and three dimensional interpretation, acquisition planning, and processing testing and optimisation.This physical model experiment proved conclusively that shallow faults with a relatively large velocity contrast across them cause 'back' faults on the seismic data which do not exist in reality. Furthermore, this experiment proved for the first time using a physical model that strike 3D marine recording is preferable to dip 3D marine recording.

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