Modelling of Real Shear Thickening Fluid (STF) Flow around a Circular Cylinder within a Channel using the Lattice Boltzmann Method

A real shear thickening fluid (STF) exhibit a complex combination of Newtonian and non-Newtonian behavior, including shear thinning and shear thickening viscosity-shear rate profile. Understanding the flow dynamics of STFs through intricate geometries, particularly in confined spaces, is crucial for the development of impact-resistant systems. To explore the flow characteristics of the real shear thickening fluids over cylindrical surface confined in a channel, we employed the Lattice Boltzmann method (LBM) within a D2Q9 framework for mesoscopic numerical simulations. The velocity and pressure profiles has been explored to the limit so that effect of real STF can been explored. Our finding are focused on the real STF effects near the cylinder and how it varies with the Reynolds number. We find that the Real shear thickening fluids exhibit a complex changes in the wake flow pattern as compared to Newtonian, power-law shear-thinning and thickening fluids. In case of Real STF, due to low shear rates, we find thinning behaviour near the centerline of the channel (i.e., in the core) of the flow where the cylinder is placed. Hence, the vortex shedding and recirculation is less intense as compare to the power-law Shear Thickening Fluid (STF) and Newtonian flows. We also find that the Real shear thickening fluid flow is more accelerated onto the cylinder and exhibit early separation as compared to the thickening or Newtonian fluid, thereby creates more pressure drag as compared to the Newtonian and pure power-law thickening fluids, whereas due to low viscosity onto the cylinder it creates less skin drag as compared to the Newtonian and pure power-law thickening fluids.