scholarly journals A NUMERICAL MODEL FOR DUNE DYNAMICS

1980 ◽  
Vol 1 (17) ◽  
pp. 95
Author(s):  
J. Sundermann ◽  
H.-J. Vollmers ◽  
W. Puls
Keyword(s):  
Sediment Transport ◽  
Path Length ◽  
Erosion Rate ◽  
Flow Model ◽  
Transport Model ◽  
Shear Velocity ◽  
Mean Flow ◽  
Sediment Transport Model ◽  
The Mean ◽  
Bed Material

A numerical sediment transport model is formulated that serves especially for the simulation of bedform mechanics. The model is based on the idea that sediment transport is determined by the erosion rate and the path length of bed material. Formulas for the erosion rate and the path length are derived from physical considerations and from measurements; they depend mainly on the local values of the shear velocity and the mean flow velocity near the bed. The behaviour of detached sediment is simulated by a Monte Carlo procedure, which is based on the mean flow velocities and the eddy viscosity. All flow properties that are needed for the sediment transport model are computed by a numerical flow model that includes two turbulence equations. Results of the flow model and the sediment transport model are compared with measured data.

Simple explicit model of liquid mean flow in region above axial impeller

1985 ◽  
Vol 50 (11) ◽  
pp. 2396-2410
Author(s):  
Miloslav Hošťálek ◽  
Ivan Fořt
Keyword(s):  
Vortex Flow ◽  
Flow Model ◽  
Quantitative Agreement ◽  
Mean Flow ◽  
Flat Bottom ◽  
Proposed Model ◽  
Minimum Number ◽  
The Mean ◽  
Model Equations ◽  
Radial Circulation

The study describes a method of modelling axial-radial circulation in a tank with an axial impeller and radial baffles. The proposed model is based on the analytical solution of the equation for vortex transport in the mean flow of turbulent liquid. The obtained vortex flow model is tested by the results of experiments carried out in a tank of diameter 1 m and with the bottom in the shape of truncated cone as well as by the data published for the vessel of diameter 0.29 m with flat bottom. Though the model equations are expressed in a simple form, good qualitative and even quantitative agreement of the model with reality is stated. Apart from its simplicity, the model has other advantages: minimum number of experimental data necessary for the completion of boundary conditions and integral nature of these data.

Sign in / Sign up

Export Citation Format

Share Document