The channel flow of a real shear thickening fluid using the Lattice Boltzmann Simulation and the Theoretical Model

Understanding a real shear-thickening fluid (STF) flowing through channel is essential in developing soft body armour applications. A real shear thickening fluid has a combination of parts-wise Newtonian, shear thinning and shear thickening regions in the viscosity-shear rate plot. The Lattice Boltzmann method (LBM), a mesoscopic simulation, is employed in a D2Q9 framework to study the flow characteristics of a real shear thickening fluid. To validate the results, we compared the numerical and analytical results obtained for fluid flow with a combination of power-law fluids with shear thickening and shear thinning behaviour, which are characterized by different power-law indexes. The effect of stress and strain rate on fluid flow has been studied. Next, we have also extended the above model to see the characteristics of the flow properties of a real shear thickening fluid having three distinct regions of Newtonian, shear thinning, and shear thickening in the viscosity-shear rate plot and discussed the results using the Lattice Boltzmann method (LBM) and with a theoretical model. We find that for the low shear rates, the Newtonian flow rate dominates, and as we keep increasing the shear rate through increasing, the thinning behaviors start to dominate, followed by the thickening phenomenon of the flow. We also find that initially, the flow begins with the Newtonian flow, and as we increase the channel height, the thinning flow starts to dominate, and for larger height channels, the thickening flow of real STF dominates.