FLOW FIELD ESTIMATION IN A S-SHAPED CHANNEL BY HIGH RESOLUTION MEASUREMENTS COMBINED WITH 3D NUMERICAL SIMULATION

摘要

At the Water Resources Institute of the University of Innsbruck experiments have been performed in an S-shaped trapezoidal channel with two bends and a slope of S = 0,005. Gravel with a mean diameter between 4,2mm and 6,4mm was used as bed material, for sediment feeding and wall roughness. Velocities were measured by means of a two-dimensional electromagnetic current meter. In areas of small water depth and low mean velocities measurement devices are not able to collect data of the whole velocity field. This deficiency can be compensated by numerical simulation. The complex flow field of curved channels implies the use of a 3D numerical model. For this purpose SSIIM-3D was applied. The collected measured data of the velocity field was used to verify the results of the numerical simulation. To investigate the areas, which are not reliably covered by the measurement, results of the numerical simulation can be favourably exploited. The same holds for the assessment of bottom shear stresses. The results obtained show that the combination of measurement and simulation enables to utilize advantages of both methods. Combined application allows dealing with certain problems in more detail and substantially improving the knowledge of flow phenomena involved.