Evaluation of the Flow Behavior in a Large-Scale Polydisperse Particle Fluidized System by an Energy Minimization Multiscale-Eulerian Combined Model

2014 ◽  
Vol 53 (36) ◽  
pp. 14113-14126 ◽  
Author(s):  
Si-Si Liu ◽  
Wen-De Xiao
Keyword(s):  
Energy Minimization ◽  
Large Scale ◽  
Flow Behavior ◽  
Combined Model ◽  
Polydisperse Particle ◽  
Fluidized System

Flow behavior of large-scale pyroclastic flows ? Evidence obtained from petrofabric analysis

1989 ◽  
Vol 51 (2) ◽  
pp. 115-122 ◽  
Author(s):  
Tadahide Ui ◽  
Keiko Suzuki-Kamata ◽  
Rumi Matsusue ◽  
Kei Fujita ◽  
Hideya Metsugi ◽  
...  
Keyword(s):  
Large Scale ◽  
Flow Behavior ◽  
Pyroclastic Flows

TYPOLOGY OF RUSSIAN INVESTORS OF FINANCIAL PYRAMIDS

2020 ◽  
pp. 9-12
Author(s):  
Y.Y. KAZANTSEV ◽  
Keyword(s):  
Financial Literacy ◽  
Large Scale ◽  
Combined Model ◽  
The Past ◽  
Economic Methods ◽  
Crowd Effect

Thanks to a large-scale campaign to increase the financial literacy of Russian citizens, financial pyramids began to seem like ghosts from the past, but in 2019 in Russia a significant number of financial pyramids were recorded. Financial literacy protects citizens from the so-called economic methods of involvement in dubious money enterprises. To a lesser extent, the layman is protected from psychological and sociological methods of influence. Psychology implies managing a person with controversial methods. Sociology offers the so-called crowd effect as an explanation of the phenomenon of mass insanity. This work classifies typical methods of attracting investors to the Russian financial pyramids, for which purpose a combined model of influence on citizens, including economic, psychological and sociological methods, is constructed. Based on this model, a typology of investors is proposed taking into account the methods of their involvement.

scholarly journals Shallow Water Magnetohydrodynamics in Plasma Astrophysics. Waves, Turbulence, and Zonal Flows

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 314 ◽  
Author(s):  
Arakel Petrosyan ◽  
Dmitry Klimachkov ◽  
Maria Fedotova ◽  
Timofey Zinyakov
Keyword(s):  
Shallow Water ◽  
Large Scale ◽  
Fundamental Problem ◽  
Flow Behavior ◽  
Magnetohydrodynamic Equations ◽  
Plasma Astrophysics ◽  
Wave Interactions ◽  
Zonal Flows ◽  
New Applications ◽  
The Universe

The purpose of plasma astrophysics is the study and description of the flow of rotating plasma in order to understand the evolution of various objects in the universe, from stars and planetary systems to galaxies and galaxy clusters. A number of new applications and observations have appeared in recent years and actualized the problem of studying large-scale magnetohydrodynamic flows, such as a thin layer under the convective zone of the sun (solar tachocline), propagation of accreting matter in neutron stars, accretion disks in astrophysics, dynamics of neutron star atmospheres, and magnetoactive atmospheres of exoplanets tidally locked with their host star. The article aims to discuss a fundamental problem in the description and study of multiscale astrophysical plasma flows by studying its general properties characterizing different objects in the universe. We are dealing with the development of geophysical hydrodynamic ideas concerning substantial differences in plasma flow behavior due to the presence of magnetic fields and stratification. We discuss shallow water magnetohydrodynamic equations (one-layer and two-layer models) and two-dimensional magnetohydrodynamic equations as a basis for studying large-scale flows in plasma astrophysics. We discuss the novel set of equations in the external magnetic field. The following topics will be addressed: Linear theory of magneto-Rossby waves, three-wave interactions and related parametric instabilities, zonal flows, and turbulence.

scholarly journals Estimating the Capacity of Urban Transportation Networks with an Improved Sensitivity Based Method

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Muqing Du ◽  
Xiaowei Jiang ◽  
Lin Cheng
Keyword(s):  
Sensitivity Analysis ◽  
Large Scale ◽  
Transportation Network ◽  
Network Capacity ◽  
Combined Model ◽  
Practical Applications ◽  
Large Scale Problems ◽  
Capacity Model ◽  
High Efficient ◽  
Equilibrium Constraint

The throughput of a given transportation network is always of interest to the traffic administrative department, so as to evaluate the benefit of the transportation construction or expansion project before its implementation. The model of the transportation network capacity formulated as a mathematic programming with equilibrium constraint (MPEC) well defines this problem. For practical applications, a modified sensitivity analysis based (SAB) method is developed to estimate the solution of this bilevel model. The high-efficient origin-based (OB) algorithm is extended for the precise solution of the combined model which is integrated in the network capacity model. The sensitivity analysis approach is also modified to simplify the inversion of the Jacobian matrix in large-scale problems. The solution produced in every iteration of SAB is restrained to be feasible to guarantee the success of the heuristic search. From the numerical experiments, the accuracy of the derivatives for the linear approximation could significantly affect the converging of the SAB method. The results also show that the proposed method could obtain good suboptimal solutions from different starting points in the test examples.

Active Flow Control of Turbulent Refractive Interfaces in Separated Shear Layers for Laser Beam Propagation

2007 ◽  
Author(s):  
Fazlul R. Zubair ◽  
Haris J. Catrakis
Keyword(s):  
Laser Beam ◽  
Large Scale ◽  
Flow Behavior ◽  
Direct Reduction ◽  
Active Flow Control ◽  
Beam Propagation ◽  
Shear Layers ◽  
Plasma Actuators ◽  
Pulsed Plasma ◽  
Laser Beam Propagation

The behavior of turbulent refractive interfaces, and means for the optimization of these interfaces, is essential in various basic and applied studies concerning the propagation of optical wavefronts such as laser beam wavefronts through turbulence or optical imaging through turbulence. In this study, the structure of turbulent refractive interfaces and aero-optical interactions along laser beam propagation paths, in unforced and forced separated compressible shear layers, are examined through use of direct imaging and pulsed plasma actuators. Dielectric-barrier discharge (DBD) pulsed plasma actuators are used to excite the flow prior to separation. Our interest is in searching for the frequencies and amplitudes of the forcing that produce direct suppression of the large scale turbulent interfaces and, thereby, direct reduction of the laser wavefront aberrations. Whole-field shadowgraph imaging of pure-air separated shear layers is conducted for control off vs. control on cases at various forcing frequencies, in order to explore the effects of plasma forcing on the large-scale flow behavior. Direct profiling of forced vs. unforced turbulence-aberrated laser wavefronts propagated transversely through shear layers is conducted using high-resolution Shack-Hartmann microlens arrays. Evidence is presented showing significant reduction of the turbulence-induced laser aberrations, for forced vs. unforced shear layers, indicating the presence of a mechanism of suppression, i.e. disorganization, of large-scale organized structures by high-frequency pulsed plasma forcing.

Establishment of Testing Methodology for Forge Welded Tubular Products

2012 ◽  
Author(s):  
Ganesan S. Marimuthu ◽  
Per Thomas Moe ◽  
Bjarne Salberg ◽  
Jan Inge Audestad
Keyword(s):  
Material Flow ◽  
Large Scale ◽  
Flow Behavior ◽  
Treatment Options ◽  
Full Scale ◽  
International Standards ◽  
Small Scale ◽  
Test Plan ◽  
Welding Machine

A state-of-the-art small-scale solid state forge welding machine has been fabricated for checking weldability by Shielded Active Gas Forge Welding (SAG-FW) of tubular products applicable predominantly for, but not limited to offshore Industries. Effective, fast and inexpensive welding and testing of joints make this small-scale method suitable for evaluating weldability of a material before starting regular qualification and fabrication in a full-scale welding machine normally located in spool base or offshore. The small-scale machine provides a complete package for pre-qualification studies, including assessment of welding conditions, material flow behavior, heat treatment options. However, there are considerable challenges relating to application of international standards of testing as well as interpretation and use of results in the context of large-scale welding. In this paper results from small-scale welding and weld characterization of an API 5L X65 quality are presented. First, a detailed test plan for analyzing the weld is outlined. This procedure is subsequently applied for checking the welds to be produced in the full-scale machine. Short-comings in using the small-scale process as well as the possible remedies are discussed in detail.

Large-scale numerical simulations of polydisperse particle flow in a silo

2016 ◽  
Vol 4 (4) ◽  
pp. 419-427 ◽  
Author(s):  
S. M. Rubio-Largo ◽  
D. Maza ◽  
R. C. Hidalgo
Keyword(s):  
Numerical Simulations ◽  
Large Scale ◽  
Particle Flow ◽  
Polydisperse Particle

Numerical Investigation of a Cryogenic Liquid Turbine Performance and Flow Behavior

2008 ◽  
Author(s):  
Wei Zhao ◽  
Jinju Sun ◽  
Hezhao Zhu ◽  
Cheng Li ◽  
Guocheng Cai ◽  
...  
Keyword(s):  
Numerical Investigation ◽  
Large Scale ◽  
Flow Behavior ◽  
Cryogenic Liquid ◽  
Air Separation ◽  
Design Flow ◽  
Suction Surface ◽  
Navier Stokes Equation ◽  
Separation Unit ◽  
Turbine Performance

A single stage cryogenic liquid turbine is designed for a large-scale internal compression air-separation unit to replace the Joule-Thompson valve and recover energy from the liquefied air during throttling process. It includes a radial vaned nozzle, and 3-dimensional impeller. Numerical investigation using 3-D incompressible Navier-Stokes Equation together with Spalart-Allmaras turbulence model and mixing plane approach at the impeller and stator interface are carried out at design and off-design flow. At design condition, recovered shaft power has amounted to 185.87 kW, and pressure in each component decreases smoothly and reaches to the expected scale at outlet. At small flow rates, flow separation is observed near the middle section of blade suction surface, which may cause local vaporization and even cavitation. To further improve the turbine flow behavior and performance, geometry parametric study is carried out. Influence of radial gap between impeller and nozzle blade rows, and nozzle stagger angle on turbine performance are investigated and clarified. Results arising from the present study provide some guidance for cryogenic liquid turbine optimal design.

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