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

摘要

Fine particle suspensions often form non-Newtonian slurries. Inmining applications these suspensions can also transport coarseparticles 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 numericalsimulation is carried out treating the fine particle suspensions ashomogeneous yield pseudo-plastic fluid i.e. shear-thinning fluidwith yield stress. Flow through a full circular pipe as well asthrough partially blocked pipes for two different bed depths areconsidered. Results are presented for flow with stationary andmoving beds. For stationary bed cases, results are compared withNewtonian fluid flow results. In all simulations, flows areassumed to be driven by a constant axial pressure gradient.Results show that non-Newtonian fluid flows are more sensitiveto change in the bed depth and the bed acts as a damper toturbulent fluctuations.