Preliminary Observations of Turbulent Flow at Culvert Inlets

This paper presents the results of preliminary observations of turbulence at the inlet to a pipe culvert using a bidirectional electromagnetic current meter (ECM). Instantaneous longitudinal and vertical components of velocity have been sampled in the approach section to a pipe culvert. The results correspond to a pipe culvert with a sharp edged inlet, r/D= 0.015, with relative headwater depths of H/D= 1.62, 1.26, and 0.96, laid on a 0.3% slope. The distributions of mean velocities, turbulence intensity, and characteristic eddy scales are shown to vary with proximity to the culvert headwall. It is demonstrated that there is a significant increase in the magnitudes of the mean velocity components and that the distribution of the turbulence intensity levels and eddy scales undergo significant changes as the flow approaches the inlet.