Entropic velocity distribution for sediment-laden flows with a modified dip estimation model at data-scarce river sites

Abstract

This study proposes an entropic velocity distribution and dip-position (y max) model for sediment-laden (SL) flows. Unlike previous studies, the proposed entropic distribution incorporates the effect of suspended-sediment (SS) and y max, to improve velocity predictions near-bed and water surface in SL flows. A new dampened mixing length for SL flows is proposed in terms of SS concentration. Moreover, the effect of channel bed roughness (k s), slope (S), SS, width (B) and flow depth (H) on y max is studied. Further, a comprehensive model for y max is proposed as a bivariate function of B/H and k s/H for natural channels. A comparative analysis is presented with the existing models, which shows the proposed equations provide higher accuracy with reduced parameters and a better representation of physical processes in SL flows. Subsequently, the proposed equations are applied at three gauged sites (Mahanadi River, India), showing its suitability to obtain velocity at data-scarce river sites.