PRELIMINARY-OBSERVATIONS OF TURBULENT-FLOW AT CULVERT INLETS

This paper presents the results of preliminary observations of turbule nce at the inlet to a pipe culvert using a bidirectional electromagnet ic current meter (ECM). Instantaneous longitudinal and vertical compon ents of velocity have been sampled in the approach section to a pipe c ulvert. The results correspond to a pipe culvert with a sharp edged in let, 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 comp onents and that the distribution of the turbulence intensity levels an d eddy scales undergo significant changes as the how approaches the in let.