The flow of non-Newtonian fluids in open channels has great implications to mining industry. When self-formed open channels flow at a sufficient gradient or slope, it can generate a certain level of turbulence. The turbulent behaviour of the transportation material can keep the particles in suspension. From previous study it has been observed that if the slope reduces, the intensity of turbulence will decline as well. The mechanism governing particle transportation in turbulent flow has been studied in the past although it not well understood. A better understanding of the mechanism operating in the turbulent flow of non-Newtonian suspensions in open channel can improve the design of many systems in the mining and mineral processing industries.

Direct numerical simulation (DNS) of the turbulent flow of non-Newtonian fluids in an open channel are modelled using a spectral element-Fourier method. The simulation of a yield–pseudoplastic fluid using the Herschel-Bulkley model agrees qualitatively with experimental results from field measurements of mineral tailing slurries. The simulation results over–predict the flow velocity by approximately 15% for the cases considered, although the source of the discrepancy is difficult to ascertain. The effect of variation in yield stress and assumed flow depth are investigated and used to assess the sensitivity of the flow to these physical parameters. This methodology is seen to be useful in designing and optimising the transport of slurries in open channels.