scholarly journals Angular Dependence of Highly Nonlinear Pulse Splitting in a Two Dimensional Granular Network

2010 ◽  
Author(s):  
D. Ngo ◽  
F. Fraternali ◽  
C. Daraio
Keyword(s):  
Experimental Data ◽  
Stainless Steel ◽  
Numerical Simulations ◽  
Angular Dependence ◽  
Granular System ◽  
Two Dimensional ◽  
Highly Nonlinear ◽  
Solitary Pulse ◽  
First Time ◽  
Pulse Splitting

We investigate experimentally and numerically the propagation of highly nonlinear signals in a branched two-dimensional granular system composed by chains of uniform spherical beads. The system consists of a Y-shaped guide with various branch angles in which stainless steel spheres are arranged. We study the dynamic behavior of a solitary pulse crossing the bifurcated interface, and splitting between the two branches. We report for the first time the dependence of the split pulses’ speed on the branch angles. Numerical simulations based on Hertzian interaction between the particles are found in agreement with the experimental data.

Influence of Inlet Boundary Conditions on Simulations of an Asymmetric Diffuser With the V2F Turbulence Model

2015 ◽  
Author(s):  
James Crawford ◽  
A. M. Birk
Keyword(s):  
Experimental Data ◽  
Boundary Conditions ◽  
Numerical Simulations ◽  
Excellent Agreement ◽  
Turbulence Model ◽  
Two Dimensional ◽  
Ansys Fluent ◽  
Inlet Velocity

A set of numerical simulations were performed on an asymmetric, two dimensional diffuser using ANSYS Fluent 14.0, a commercially available RANS based CFD code. The ν′2¯-f turbulence model, which has previously been shown to be a good model for this geometry, was implemented through a user defined function, and the influence of inlet boundary conditions was evaluated. It was shown that the inlet velocity and turbulence profiles had a significant effect on the calculated performance of the diffuser, especially in terms of the onset of diffuser stall. It was shown that when the boundary conditions were set appropriately, excellent agreement with LES and experimental data was obtained.

scholarly journals Dilatancy of frictional granular materials under oscillatory shear with constant pressure

2021 ◽  
Vol 249 ◽  
pp. 02011
Author(s):  
Daisuke Ishima ◽  
Hisao Hayakawa
Keyword(s):  
Friction Coefficient ◽  
Numerical Simulations ◽  
Granular Materials ◽  
Strain Amplitude ◽  
Constant Pressure ◽  
Oscillatory Shear ◽  
Granular System ◽  
Mutual Friction ◽  
Two Dimensional ◽  
Confinement Pressure

We perform numerical simulations of a two-dimensional frictional granular system under oscillatory shear confined by constant pressure. We found that the system undergoes dilatancy as the strain increases. We confirmed that compaction also takes place at an intermediate strain amplitude for a small mutual friction coefficient between particles. We also found that compaction depends on the confinement pressure while dilatancy little depends on the pressure.

Numerical Simulations of Tsunami Wave Generation by Submarine and Aerial Landslides Using RANS and SPH Models

2009 ◽  
Author(s):  
Kaushik Das ◽  
Ron Janetzke ◽  
Debashis Basu ◽  
Steve Green ◽  
John Stamatakos
Keyword(s):  
Experimental Data ◽  
Free Surface ◽  
Numerical Simulations ◽  
Tsunami Wave ◽  
Wave Generation ◽  
Numerical Results ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Tsunami Waves ◽  
Time Histories

Tsunami wave generation by submarine and aerial landslides is examined in this paper. Two different two-dimensional numerical methods have been used to simulate the time histories of fluid motion, free surface deformation, shoreline movement, and wave runup from tsunami waves generated by aerial and submarine landslides. The first approach is based on the Navier-Stokes equation and the volume of fluid (VOF) method: the Reynolds Averaged Navier-Stokes (RANS)-based turbulence model simulates turbulence, and the VOF method tracks the free surface locations. The second method uses Smoothed Particle Hydrodynamics (SPH)—a numerical model based on a fully Lagrangian approach. In the current work, two-dimensional numerical simulations are carried out for a freely falling wedge representing the landslide and subsequent wave generations. Numerical simulations for the landslide-driven tsunami waves have been performed with different values of landslide material densities. Numerical results obtained from both approaches are compared with experimental data. Simulated results for both aerial and submerged landslides show the complex flow patterns in terms of the velocity field, shoreline evolution, and free-surface profiles. Flows are found to be strongly transient, rotational, and turbulent. Predicted numerical results for time histories of free-surface fluctuations and the runup/rundown at various locations are in good agreement with the available experimental data. The similarity and discrepancy between the solutions obtained by the two approaches are explored and discussed.

Nonlinear Cord-rubber Composites

1990 ◽  
Vol 18 (3) ◽  
pp. 191-200 ◽  
Author(s):  
S. K. Clark ◽  
R. N. Dodge
Keyword(s):  
Experimental Data ◽  
Nonlinear Equations ◽  
Analytical Method ◽  
Analytical Procedure ◽  
Rubber Matrix ◽  
Two Dimensional ◽  
Rubber Composites ◽  
Forward Prediction ◽  
Highly Nonlinear ◽  
Elastomeric Composites

Abstract An analytical method is proposed for the prediction of load-deflection and stress-strain relations in two-dimensional elastomeric composites where the properties are highly nonlinear. Such materials are represented by various textile cords used as reinforcements in a rubber matrix. The analytical procedure involves a forward prediction process for simultaneous nonlinear equations and can readily be implemented for automated computer use. Experiments on nonlinear tubes are reported and computation of load-deflection relationships observed in those experiments are compared with experimental data. The predictions generally agree with the observed behavior.

scholarly journals Highly nonlinear pulse splitting and recombination in a two-dimensional granular network

2010 ◽  
Vol 82 (3) ◽  
Author(s):  
C. Daraio ◽  
D. Ngo ◽  
V. F. Nesterenko ◽  
F. Fraternali
Keyword(s):  
Two Dimensional ◽  
Highly Nonlinear ◽  
Pulse Splitting

scholarly journals Analysis of Mobility in Graded-Channel SOI Transistors Aiming at Circuit Simulation

2020 ◽  
Vol 15 (2) ◽  
pp. 1-5
Author(s):  
Lucas Mota Barbosa da Silva ◽  
Bruna Cardoso Paz ◽  
Michelly De Souza
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Circuit Simulation ◽  
Two Dimensional ◽  
Soi Mosfet ◽  
Low Field ◽  
Field Mobility ◽  
Effective Mobility ◽  
Low Field Mobility

This work presents an analysis of the behavior of the effective mobility of graded-channel FD SOI transistors using an Y-Function-based technique. Low field mobility, linear and quadratic attenuation factors were extracted from two-dimensional numerical simulations. The influence of the length of both channel regions over these parameters was analyzed. The parameters extracted from experimental data were used in a SPICE simulator, showing that it is possible to simulated GC SOI MOSFET using a regular SOI MOSFET model, by adjusting its parameters.

scholarly journals Numerical simulations of dense clouds on steep slopes: application to powder-snow avalanches

2004 ◽  
Vol 38 ◽  
pp. 379-383 ◽  
Author(s):  
Jocelyn Étienne ◽  
Pierre Saramito ◽  
Emil J. Hopfinger
Keyword(s):  
Numerical Simulations ◽  
Local Density ◽  
Direct Numerical Simulations ◽  
Two Dimensional ◽  
Snow Avalanches ◽  
Velocity Variations ◽  
Steep Slopes ◽  
First Time ◽  
Spatial Growth Rate ◽  
Good Agreement

AbstractIn this paper, two-dimensional direct numerical simulations (DNS) of dense clouds moving down steep slopes are presented for the first time. The results obtained are in good agreement with the overall characteristics, i.e. the spatial growth rate and velocity variations, of clouds studied in the laboratory. In addition to the overall flow structure, DNS provide local density and velocity variations inside the cloud, not easily accessible in experiments. The validity of two-dimensional simulations as a first approach is confirmed by the dynamics of the flow and by comparison with experimental results. The interest of the results for powder-snow avalanches is discussed; it is concluded that two-dimensionality is acceptable and that large density differences need to be taken into account in future simulations.

Numerical and Experimental Investigation of Nonlinear Shallow Water Sloshing

2013 ◽  
Vol 14 (2) ◽  
Author(s):  
Benjamin Bouscasse ◽  
Matteo Antuono ◽  
Andrea Colagrossi ◽  
Claudio Lugni
Keyword(s):  
Experimental Data ◽  
Experimental Investigation ◽  
Numerical Simulations ◽  
Shallow Water ◽  
Experimental Analysis ◽  
Large Amplitude ◽  
Large Range ◽  
Three Dimensional ◽  
Extensive Study ◽  
Two Dimensional

AbstractA numerical and experimental analysis of sloshing phenomena (i.e. violent fluid motions inside a tank) has been conducted in shallow water regimes. A narrow tank has been used to limit three-dimensional effects and allow for an extensive study of two-dimensional waves. A large range of experimental data from small to large amplitude sway motions has been considered for five different filling heights. The numerical simulations have been performed to cover the configurations where no experiments were available and provide an exhaustive description of the shallow-water sloshing motion. Specifically, the numerical simulations have been performed through a

Comparison of Recovery and Recrystallization in Stainless Steel Following Plane-Wave Shock Loading and Explosive Forming

1970 ◽  
Vol 28 ◽  
pp. 428-429 ◽  
Author(s):  
J. A. Korbonski ◽  
L. E. Murr
Keyword(s):  
Stainless Steel ◽  
Shock Loading ◽  
Pressure Pulse ◽  
Shock Pressure ◽  
304 Stainless Steel ◽  
Strain Rates ◽  
Two Dimensional ◽  
Aisi 304 Stainless Steel ◽  
Aisi 304 ◽  
Explosive Forming

Comparison of recovery rates in materials deformed by a unidimensional and two dimensional strains at strain rates in excess of 104 sec.−1 was performed on AISI 304 Stainless Steel. A number of unidirectionally strained foil samples were deformed by shock waves at graduated pressure levels as described by Murr and Grace. The two dimensionally strained foil samples were obtained from radially expanded cylinders by a constant shock pressure pulse and graduated strain as described by Foitz, et al.

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