An analytical study on turbulence with mixed-flow model and two-phase model

Suspended sediment is carried by turbulent water flows in rivers. Traditional sediment-laden flow analysis treats the suspension as a mixed liquid, and recent two-phase flow model enables separate velocity measurement of the two coupling phases. A simplified theoretical analysis was presented to discuss the differences between the two models in reporting turbulence intensity in experimental research. The turbulence intensity of the mixture is lower than the weighted average of those of the two phases in mixed-flow experiments. The mixture's turbulence intensity becomes higher than the average of the two phases in two-phase experiments due to the presence of velocity lag. The same set of data may lead to either an underestimation or an overestimation of actual turbulence levels when different models are used.