Vibrational flow of non-Newtonian fluids

Abstract The flow of a time-independent fluid through a vibrated tube is studied both numerically by CFD simulation and experimentally. The effects are studied for Newtonian and non-Newtonian fluids which obey Bingham plastic, power-law or Herschel–Bulkley behaviour. The superimposed mechanical oscillations have no effect on the flow of Newtonian fluids, but can greatly influence that of shear-dependent fluids. Flow enhancement is obtained with shear-thinning fluids whereas flow reduction occurs when a shear-thickening fluid is vibrated. The effects of the various rheological parameters are investigated, and the flow behaviour index emerges as the most influential. The enhancement is a function of both vibration frequency and amplitude, but the same enhancement is generated with different amplitude–frequency combinations that correspond to the same peak acceleration. The CFD predictions are in both qualitative and quantitative agreement with experimental measurements.