Author:

Keywords:

Science & Technology, Technology, Physical Sciences, Engineering, Civil, Water Resources, Engineering, Acoustic Doppler velocimeter, boundary-free shear flow turbulence, buoyancy-driven flows, experimental facilities, particle-laden flows, auspended sediments, turbulent jets, turbulent plumes, ACOUSTIC DOPPLER-VELOCIMETER, SUSPENDED SEDIMENT, COHESIVE SEDIMENT, VELOCITY, MUD, NOISE, JETS, ADCP, 0905 Civil Engineering, 0907 Environmental Engineering, Environmental Engineering, 4005 Civil engineering

Abstract:

© 2015 International Association for Hydro-Environment Engineering and Research. New methods have been developed to extract turbulent fluxes of momentum and fine sediments from Acoustic Doppler Velocimeter (ADV) data. The methods were validated with turbidity plume experiments. The ADV's backscatter amplitude signal was used to determine the sediment concentration and its turbulent fluctuations. However, different kinds of noise are found in the backscatter amplitude and the velocity signals, which are polluting the turbulent fluxes results. Therefore, spectral noise correction methods have been developed, which allow more accurate quantification of turbulent velocity and sediment concentration fluctuations. The techniques are applied to two benchmark cases of a vertical sediment-laden jet. Reynolds stresses, turbulent intensity of velocity and sediment concentration as well as turbulent sediment fluxes are shown to agree well with two-fluid plume measurements reported in the literature. The methods presented in this paper can be applied to the processing of measurements in cohesive sediment plumes, turbidity currents or mixing layers in the absence of, or in stable, flocculation.