The turbulent transport of suspended sediment in open channels

Fine sediment is carried in suspension by turbulent flow under steady conditions, provided that similar material is present on the bed. An equation is deduced for the variation with depth of the sediment concentration for two-dimensional flow. It is found necessary to take account of the volume occupied by the sediment, this being particularly important near the bed. The result agrees with recent observations by Vanoni (1946). A velocity distribution obtained by Kármán, using a linear variation of shear with depth, is generalized by omitting the infinite velocity gradient condition at the bed and is found to be in good agreement with Vanoni’s measurements. A slight difference is found between the mean sediment velocity in the direction of flow and that of the water.

Download Full-text

Turbulent diffusion in two-dimensional, strongly magnetized plasmas

Journal of Plasma Physics ◽

10.1017/s0022377800002695 ◽

1985 ◽

Vol 34 (1) ◽

pp. 77-94 ◽

Cited By ~ 15

Author(s):

H. L. Pécseli ◽

T. Mikkelsen

Keyword(s):

Turbulent Transport ◽

Low Frequency ◽

Two Dimensions ◽

Magnetized Plasma ◽

Two Dimensional ◽

Drift Wave Turbulence ◽

Field Fluctuations ◽

The Mean ◽

Wavenumber Spectrum ◽

Convective Cells

Particle diffusion is investigated in a strictly two-dimensional collisionless guiding-centre model for a strongly magnetized plasma. An analytical expression is presented for the entire time variation of the mean square test-particle displacement in the limit of low-frequency, strongly turbulent, electric field fluctuations. The analysis relies on an explicit integral expression for the Lagrangian autocorrelation function in terms of the Eulerian wavenumber spectrum and a time-varying weight function. Bohm diffusion is discussed by means of a simple model spectrum. The analysis applies for turbulent transport associated with electrostatic convective cells, magnetostatic cells and drift wave turbulence with the assumption of local homogeneity and isotropy in two dimensions.

Download Full-text

Correlations between the instantaneous velocity gradient and the evolution of scale-to-scale fluxes in two-dimensional flow

Physical Review E ◽

10.1103/physreve.92.033017 ◽

2015 ◽

Vol 92 (3) ◽

Cited By ~ 1

Author(s):

Yang Liao ◽

Nicholas T. Ouellette

Keyword(s):

Velocity Gradient ◽

Instantaneous Velocity ◽

Two Dimensional ◽

Dimensional Flow ◽

Two Dimensional Flow

Download Full-text

THE DISSIPATION OF WAVE ENERGY BY TURBULENCE

Coastal Engineering Proceedings ◽

10.9753/icce.v17.52 ◽

1980 ◽

Vol 1 (17) ◽

pp. 52

Author(s):

Yu Kuang-ming

Keyword(s):

General Theory ◽

Wave Energy ◽

Laboratory Experiments ◽

Velocity Fields ◽

Mixing Length ◽

Two Dimensional ◽

Two Dimensional Flow ◽

The Mean ◽

Vertical Gradients ◽

Horizontal Area

This paper first gives a brief review of the existing research works on the laws governing the dissipation of rave energy by turbulence. Starting from the general theory of turbulent motion and the writer's suggestion in regard to the mixing length of water particles in two-dimensional flow and making use of the principle of dimensional analysis and the trochidal rave theory, a formula has been derived to compute the mean dissipation per unit time and per unit horizontal area of wave energy due to turbulence. The formula takes the horizontal and vertical gradients of both the horizontal and vertical velocity fields into consideration. Coefficient in the formula has been determined through laboratory experiments.

Download Full-text

A one-dimensional self-gravitating stellar gas

Symposium - International Astronomical Union ◽

10.1017/s0074180900105261 ◽

1966 ◽

Vol 25 ◽

pp. 46-48 ◽

Cited By ~ 2

Author(s):

M. Lecar

Keyword(s):

Gravitational Field ◽

Phase Space ◽

Motion Picture ◽

Space Distribution ◽

Two Dimensional ◽

One Dimensional ◽

Phase Space Distribution ◽

Dimensional Phase Space ◽

The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

Download Full-text