NUMERICAL SIMULATION OF FLOW FIELD AND SEDIMENT CONCENTRATION IN FOREBAY

摘要

In present days, use of numerical techniques to simulate complicated problems including flow fields and sediment transport is rapidly increasing. To use computer models in practical conditions, it should be simple, fast and economical. In this paper a 2-D numerical model is presented to simulate the flow field and sediment concentration in a rectangular forebay. Flow is modelled as a turbulent surface jet. Flow field is solved by integrating governing equations (continuity and momentum) by strip-integral method. To account for turbulent shear stresses, k-ε turbulence model is used. To solve the governing equations for k and ε, a proper distribution is used for both parameters in vertical directions and unknown coefficients in the general distribution are found in the calculation process. When flow filed is calculated the convection-diffusion equation for sediment concentration is integrated in the flow domain. To validate the present numerical simulation, the results are compared with the experimental data in two stages. First, the flow field is compared with the empirical results which show fairly good agreement. In the second stage, the an experimental work on the efficiency of a sediment stilling basin was used and the present numerical results also shows fairly good agreement.