Drag and uncertainty of power-law fluid flows in fractal multiparticle systems

In this study, new approaches are developed to predict the drag and assess its potential uncertainty of a nonNewtonian fluid in a multiparticle system. First, a new and simpler approximate solution of power-law fluid flow is developed using the free surface cell model. Second, the uncertainty of drag in a fractal multiparticle system is investigated by treating the heterogeneous voidage in the system as a truncated power-law fractal distribution. The results demonstrate that the developed simpler approximate solution works well compared to the analytical solutions and experimental data. Incorporating truncated power-law fractal voidage can better capture the experimental data. The voidage heterogeneity increases the drag of the power-law fluid moving through the multiparticle system. Strong shear-thinning effects of power-law fluids and high mean voidage diminish the effect of voidage heterogeneity. The flow drag of power-law fluid in the heterogeneous multiparticle system decreases with increasing fractal dimension.