Bed Load Transport and Bed Deformation in Alluvial Channel with Continuous Expansion and Contraction

A two-dimensional stability analysis of the flow in a straight alluvial channel has been carried out, using the vorticity transport equation. In the analysis an attempt has been made to account for the influence of gravity on bed-load transport, and this turned out to change the stability quite significantly.In the case of instability, the further growth of the dunes has been investigated using a second-order approximation, This nonlinear theory explains the experimental fact that the dunes very soon become asymmetric.

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Similarity Laws of Distorted Model with a Movable Bed and its Validity

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.383-390.4413 ◽

2011 ◽

Vol 383-390 ◽

pp. 4413-4423

Author(s):

Bing Qian Wei ◽

Hong Yun Xun ◽

Rong Ge Xiao ◽

Wen Qiang Meng

Keyword(s):

Bed Load ◽

Bed Deformation ◽

Deformation Equation ◽

Bed Form ◽

Load Transport ◽

Bed Load Transport ◽

Dimensional Equation ◽

Movable Bed ◽

Distorted Model ◽

Similarity Laws

The theoretical backing of the similarity laws obtained from dual dimensionless parameters of the bed-form classification diagram is given by solving the equations of similarity conditions which is obtained from 1-Dimensional equation of motion, continuity equation, bed deformation equation and the formula of bed load transport. Secondly, the validity of the similarity laws is confirmed by comparing the bed form of distorted model experiment with that of undistorted model experiments performed by Hokkaido Development Bureau (H.D.B.). And also the fact that the height of bar in a gentle curved river channel can be estimated by the result of distorted model of straight flume is found.

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NUMERICAL MODEL TO SIMULATE THE EROSION ON THE SLOPE DUE TO OVERTOPPING

Science and Technology Development Journal ◽

10.32508/stdj.v13i3.2156 ◽

2010 ◽

Vol 13 (3) ◽

pp. 78-87

Author(s):

Hoai Cong Huynh

Keyword(s):

Numerical Model ◽

Flow Model ◽

Bed Load ◽

Experiment Data ◽

Step Method ◽

Morphological Model ◽

Load Transport ◽

Bed Load Transport ◽

The Finite Difference Method ◽

Good Agreement

The numerical model is developed consisting of a 1D flow model and the morphological model to simulate the erosion due to the water overtopping. The step method is applied to solve the water surface on the slope and the finite difference method of the modified Lax Scheme is applied for bed change equation. The Meyer-Peter and Muller formulae is used to determine the bed load transport rate. The model is calibrated and verified based on the data in experiment. It is found that the computed results and experiment data are good agreement.

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