ABSTRACT

In the literature, a lot of models are found to predict the concentration profile based on diffusion theory. It is a simple and highly accurate way to calculate the concentration profile of the open channel. The diffusion theory can also be used to study the sand hydraulic transport in pipelines. The boundary condition is the main difference. First, the maximum velocity point is on the free surface of the open channel, but the pipeline’s boundary is circle-shaped with no free surface, and the maximum velocity point is located near the center of the cross-section. Besides, the driven force is gravity for the open channel flow, whereas the differential pressure is the power of slurry flow in pipelines. These two different situations have an influence on sand diffusion.