scholarly journals SOME SAND TRANSPORT PHENOMENA OH COASTS WITH BARS

1970 ◽  
Vol 1 (12) ◽  
pp. 54 ◽  
Author(s):  
M. Dyhr-Nielson ◽  
Torben Sorensen
Keyword(s):  
Fluid Dynamics ◽  
Transport Phenomena ◽  
Present Knowledge ◽  
Quantitative Approach ◽  
Sand Transport ◽  
Shore Zone ◽  
Secondary Currents ◽  
Sediment Movement ◽  
System A ◽  
Complex Phenomena

Longshore wave currents and their influence on the sand transport phenomena m the shore zone have attracted the attention of numerous researchers. Also the existence of transverse, secondary currents, superposing the longshore component, has been known for years, but less attention has been given to analysis of their effect on the sediment movement. This paper presents some examples of the influence, these relatively weak transverse currents may have on the processes in the shore zone. They have a parallel in the effect of secondary currents in alluvial streams, which, although weak, give use to such an impressive phenomenon as meandering. All conclusions below are based on simple, qualitative considerations of the physics of the system. A strict mathematical, quantitative approach to the problem does not seem possible with the present knowledge of the fluid dynamics in the shore zone, and much further research into these complex phenomena remains, of course, necessary.

scholarly journals Investigation of sand transport in an undulated pipe using computational fluid dynamics

2018 ◽  
Vol 162 ◽  
pp. 747-762 ◽  
Author(s):  
Roland Tebowei ◽  
Mamdud Hossain ◽  
Sheikh Zahidul Islam ◽  
Mohamad Ghazi Droubi ◽  
Gbenga Oluyemi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Sand Transport

scholarly journals Time averaged properties along unstable periodic orbits and chaotic orbits in two map systems

2008 ◽  
Vol 15 (4) ◽  
pp. 675-680 ◽  
Author(s):  
Y. Saiki ◽  
M. Yamada
Keyword(s):  
Fluid Dynamics ◽  
Periodic Orbit ◽  
Periodic Orbits ◽  
Space Physics ◽  
Unstable Periodic Orbits ◽  
Unstable Periodic Orbit ◽  
Geophysical Fluid Dynamics ◽  
Chaotic Orbits ◽  
Low Dimensional ◽  
Complex Phenomena

Abstract. Unstable periodic orbit (UPO) recently has become a keyword in analyzing complex phenomena in geophysical fluid dynamics and space physics. In this paper, sets of UPOs in low dimensional maps are theoretically or systematically found, and time averaged properties along UPOs are studied, in relation to those of chaotic orbits.

Fluid Dynamics in Airway Bifurcations: II. Secondary Currents

2001 ◽  
Vol 13 (4) ◽  
pp. 281-289
Author(s):  
T. B. Martonen, X. Guan, R. M. Schr
Keyword(s):  
Fluid Dynamics ◽  
Secondary Currents

Knowledge Extraction from Unknown Environment by Artificial-life Approach

1999 ◽  
Vol 3 (4) ◽  
pp. 215-222
Author(s):  
Ryoji Sawa ◽  
◽  
Yuji Makita ◽  
Masafumi Hagiwara
Keyword(s):  
Information Processing ◽  
Artificial Life ◽  
Actual World ◽  
Gene Evolution ◽  
Knowledge Extraction ◽  
Present Knowledge ◽  
Difficult Situation ◽  
Living Things ◽  
Route Finding ◽  
Complex Phenomena

Studies that target excellent information processing systems simulating life systems include the artificial-life (AL) incorporating emergence phenomenon - individual elements interacting based on lower level rules to generate higher level complex phenomena. Living things conserve species by replicating genes. We propose knowledge extraction promoting emergence by an AL approach incorporating living conservation of species and gene evolution. The proposed system consists of an AL environment and a knowledge extraction network. In the AL environment, individual elements interact and obtained data is input to the knowledge extraction network to present knowledge as a form of rules. Sets of rules are regarded as genes individual elements bequeath and new elements inherit these genes. We deal with a route-finding problem that, in simulation, sets a difficult situation whose goal is unknown, considering the actual world. Rules on route maps are extracted and extracted sets of rules are regarded as genes whose evolution is simulated through gene combination. We verified that the system finds routes effectively using evolved genes in a map made complex by combining maps.

scholarly journals Dawn–dusk asymmetries in the coupled solar wind–magnetosphere–ionosphere system: a review

2014 ◽  
Vol 32 (7) ◽  
pp. 705-737 ◽  
Author(s):  
A. P. Walsh ◽  
S. Haaland ◽  
C. Forsyth ◽  
A. M. Keesee ◽  
J. Kissinger ◽  
...  
Keyword(s):  
Solar Wind ◽  
Present Knowledge ◽  
Earth’S Magnetosphere ◽  
External Influences ◽  
System A ◽  
And Topology ◽  
Earth's Magnetosphere ◽  
Key Aspects

Abstract. Dawn–dusk asymmetries are ubiquitous features of the coupled solar-wind–magnetosphere–ionosphere system. During the last decades, increasing availability of satellite and ground-based measurements has made it possible to study these phenomena in more detail. Numerous publications have documented the existence of persistent asymmetries in processes, properties and topology of plasma structures in various regions of geospace. In this paper, we present a review of our present knowledge of some of the most pronounced dawn–dusk asymmetries. We focus on four key aspects: (1) the role of external influences such as the solar wind and its interaction with the Earth's magnetosphere; (2) properties of the magnetosphere itself; (3) the role of the ionosphere and (4) feedback and coupling between regions. We have also identified potential inconsistencies and gaps in our understanding of dawn–dusk asymmetries in the Earth's magnetosphere and ionosphere.

The Mathematical Modelling of Transport Phenomena in Non-Transferred Plasma Systems: Accomplishments and Unresolved Problems

1987 ◽  
Vol 98 ◽  
Author(s):  
A. H. Dilawari ◽  
J. Szekely
Keyword(s):  
Transport Phenomena ◽  
Computational Fluid Mechanics ◽  
Plasma Arc ◽  
Critical Comparison ◽  
System A ◽  
Turbulent Transition ◽  
Standard Application ◽  
Inlet Conditions ◽  
System Properties ◽  
Future Work

ABSTRACTAn overview is presented of transport phenomena in non-transferred plasma arc systems. It has been shown that while the modelling of these systems involves the standard application of computational fluid mechanics techniques, numerous pitfalls may be encountered in practice. A detailed discussion of these is presented, with emphasis on the torch inlet conditions, the effect of swirl, the temperature dependence of the system properties and the laminar-turbulent transition in the system. A critical comparison is presented with experimental measurements, and the necessary future work is also outlined.

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