Velocity Distribution in Uniform Sediment‐Laden Flow

A theoretical model to predict the velocity distribution for sediment‐laden flow is developed by means of a new mixing‐length concept. The solution is obtained as a function of the vertical sediment concentration. The von Kármán coefficient is independent on suspended load and equal to 0.4. The model is applicable to an alluvial‐bed condition as well as a flat‐bed condition. The possibility of adapting the model to clear‐water flow is also discussed. For clear‐water flow, the velocity equation consists of a logarithmic term and power‐series terms that explain the wake effect. The theoretical velocity distribution for sediment‐laden flow departs from the logarithmic law in the outer layer. The magnitude of the departure is larger with the increase in the sediment load. The numerical calculation is carried out and its prediction is compared to five independent sets of experimental data previously obtained. The theoretical result shows good agreement in the whole flow layer with these experimental results.