Estimating Drag Forces on Suspended and Laid-on-Seafloor Pipelines Caused by Clay-Rich Submarine Debris Flow Impact

2010 ◽  
pp. 93-103
Author(s):  
A. Zakeri
Keyword(s):  
Debris Flow ◽  
Drag Forces

Submarine Debris Flow Impact on Pipelines: Drag Forces, Mitigation and Control

2008 ◽  
Author(s):  
Arash Zakeri ◽  
Kaare Hoeg ◽  
Farrokh Nadim
Keyword(s):  
Debris Flow ◽  
Drag Forces ◽  
And Control

The E-ring: interactions with plasma and implications for its evolution

1984 ◽  
Vol 75 ◽  
pp. 599-602
Author(s):  
T.V. Johnson ◽  
G.E. Morfill ◽  
E. Grun
Keyword(s):  
Time Scale ◽  
Particle Density ◽  
High Energy ◽  
Particle Removal ◽  
Density Region ◽  
Drag Forces ◽  
Orbit Evolution ◽  
History Of ◽  
Ring Particle ◽  
Ring Material

A number of lines of evidence suggest that the particles making up the E-ring are small, on the order of a few microns or less in size (Terrile and Tokunaga, 1980, BAAS; Pang et al., 1982 Saturn meeting; Tucson, AZ). This suggests that a variety of electromagnetic and plasma affects may be important in considering the history of such particles. We have shown (Morfill et al., 1982, J. Geophys. Res., in press) that plasma drags forces from the corotating plasma will rapidly evolve E-ring particle orbits to increasing distance from Saturn until a point is reached where radiation drag forces acting to decrease orbital radius balance this outward acceleration. This occurs at approximately Rhea's orbit, although the exact value is subject to many uncertainties. The time scale for plasma drag to move particles from Enceladus' orbit to the outer E-ring is ~104yr. A variety of effects also act to remove particles, primarily sputtering by both high energy charged particles (Cheng et al., 1982, J. Geophys. Res., in press) and corotating plasma (Morfill et al., 1982). The time scale for sputtering away one micron particles is also short, 102 - 10 yrs. Thus the detailed particle density profile in the E-ring is set by a competition between orbit evolution and particle removal. The high density region near Enceladus' orbit may result from the sputtering yeild of corotating ions being less than unity at this radius (e.g. Eviatar et al., 1982, Saturn meeting). In any case, an active source of E-ring material is required if the feature is not very ephemeral - Enceladus itself, with its geologically recent surface, appears still to be the best candidate for the ultimate source of E-ring material.

Saturn's E, G and F rings: modulated by the plasma sheet

1984 ◽  
Vol 75 ◽  
pp. 597
Author(s):  
E. Grün ◽  
G.E. Morfill ◽  
T.V. Johnson ◽  
G.H. Schwehm
Keyword(s):  
Solar Wind ◽  
Direct Contact ◽  
Transport Processes ◽  
Time Variable ◽  
Dust Particles ◽  
Spatial Diffusion ◽  
Drag Forces ◽  
Orbit Perturbation ◽  
Time Variations ◽  
F Ring

ABSTRACTSaturn's broad E ring, the narrow G ring and the structured and apparently time variable F ring(s), contain many micron and sub-micron sized particles, which make up the “visible” component. These rings (or ring systems) are in direct contact with magnetospheric plasma. Fluctuations in the plasma density and/or mean energy, due to magnetospheric and solar wind processes, may induce stochastic charge variations on the dust particles, which in turn lead to an orbit perturbation and spatial diffusion. It is suggested that the extent of the E ring and the braided, kinky structure of certain portions of the F rings as well as possible time variations are a result of plasma induced electromagnetic perturbations and drag forces. The G ring, in this scenario, requires some form of shepherding and should be akin to the F ring in structure. Sputtering of micron-sized dust particles in the E ring by magnetospheric ions yields lifetimes of 102to 104years. This effect as well as the plasma induced transport processes require an active source for the E ring, probably Enceladus.

NUMERICAL SIMULATION OF THE PRESSURE AND DRAG FORCES AROUND THE AHMED BODY UNDER TURBULENT FLOW

2020 ◽  
Author(s):  
Jalusa Maria da Silva Ferrari ◽  
Luciano Noleto ◽  
jhon goulart ◽  
Fábio Kayser
Keyword(s):  
Numerical Simulation ◽  
Turbulent Flow ◽  
Drag Forces ◽  
Ahmed Body
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