Turbulent Flow of Non-Newtonian Fluids in a Partially Blocked Pipe

Fine particle suspensions often form non-Newtonian slurries. In mining applications these suspensions can also transport coarse particles that can form a settled bed on the bottom of the pipe. These settled solid particles can be stationary or move as a bed, depending on the flow conditions. In this study, direct numerical simulation is carried out treating the fine particle suspensions as homogeneous yield pseudo-plastic fluid i.e. shear-thinning fluid with yield stress. Flow through a full circular pipe as well as through partially blocked pipes for two different bed depths are considered. Results are presented for flow with stationary and moving beds. For stationary bed cases, results are compared with Newtonian fluid flow results. In all simulations, flows are assumed to be driven by a constant axial pressure gradient. Results show that non-Newtonian fluid flows are more sensitive to change in the bed depth and the bed acts as a damper to turbulent fluctuations