Experiments were performed in a hydraulic flume with varying flow depth and bed roughness. Rectangular ribs and two-dimensional dune-shaped obstacles were placed on the flume bottom to simulate different bed roughness conditions. Laser Doppler Velocimetry (LDV) measurements were made to obtain the vertical velocity profiles at various locations. Large-Scale Particle Image Velocimetry (LSPIV) measurements were made to determine the velocity distribution at the free-surface. Large-Eddy Simulation (LES) with qrigid-lidq approximation for the free-surface was used to numerically simulate the flow over rib and dune geometries.Figure 4.27 -ua#39;wa#39; vs. z/h plot in the outer region for flow over ribs with h = 8.5 cm and A = 9 cm (R05). 0.1 Ap 0 0.1 0.2 0.3 0.4 alt;Uagt; (m/s) Figure 4.28 Location of the virtual origin as the z-intersect of the linear part or the velocity profile in semi-log plot for flow over dunes with 6 cm depth (D01). ... A 2kA A _ ^Aagt; 0.2 - A X. A X A A o - aN^aAa \ A tdr i- a a ** -*-alt;uagt; Flow code // (m) JL(m) Method D01 0.08 0.4 Exp.
|Title||:||Large-scale Roughness Effect on Free-surface and Bulk Flow Characteristics in Open-channel Flows|
|Publisher||:||ProQuest - 2006|