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Abstract

The prediction and calculation of transport phenomena of suspended solids in turbulent flowing water is essential in hydraulic engineering as well as in the environmental field. A mathematical model, based on the diffusion-convection equation, has been developed for the simulation of various sedimentation processes of cohesionless sand-sized grains in turbulent free surface flows. The fall velocity distribution of the solids can be measured by means of a computerised sedimentation balance. Sensitivity analysis demonstrates the influence of the fall velocity distribution and the scatter of the other input parameters on the possible variation of sedimentation rates and the vertical distribution of the sediment. The sedimentation rates of sand-sized particles are much more affected by the initial concentration profile than by the resuspension coefficient at the bottom. Only for resuspension coefficients roughly greater than 0.75 (equilibrium suspended sediment transport = 1) the sedimentation is affected more significantly. Comparisons between numerical results and data of experiments in a laboratory flume, as well as field data, have proved the applicability of the mathematical model and shown that scattering of the input parameters has to be taken into account.

Additional information

Authors: BECHTELER W UNIV. DER BUNDESWEHR, MUENCHEN, D SCHRIMPT W CEC-BRUSSLES , UNIV. DER BUNDESWEHR, MUENCHEN, D;CEC-BRUSSLES
Bibliographic Reference: 7TH INTERNATIONAL CONFERENCE ON COMPUTATIONAL METHODS IN WATER RESOURCES, CAMBRIDGE/USA, JUNE 13-17, AVAILABILITY: CEC-LUXEMBOURG, DG XIII/A2, BP 1907, MENTIONING PAPER ORA 33811 E
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