Author(s): Joana Baltazar; Gokcen Bombar; Elsa Alves; Antonio Heleno Cardoso
Keywords: Diversion; Submerged vanes; Turbulence
Abstract: In this study the turbulence of the flow in the vicinity of a lateral water diversion was experimentally investigated under two different set-ups, namely, without submerged vanes (NV) and in the presence of a vane field (VF). The water discharge ratio of ≈0.2 was imposed under live bed flow conditions with 0.266 kg/min sediment feeding rate and the experiments were conducted until the bed equilibrium was reached. 3D velocity measurements were made at more than 5000 points per set-up, through ADV, working with a sampling frequency of 100 Hz. Turbulence intensity and Reynolds shear-stresses were derived from the measurements and discussed. They were concluded to be in excellent agreement with the average mean velocity field presented and discussed in a previous paper. The results also shed light on the mechanisms that explain the decrease of diverted sediment load in the presence of a vane field placed in the main channel in front of the diversion entrance.