Steady flow of a non-Newtonian Carreau fluid across an unconfined circular cylinder

Abstract

The flow of a non-Newtonian, Carreau fluid, directed normally to a horizontal, stationary, circular cylinder is considered in the present paper. The problem is investigated numerically using the commercial code ANSYS FLUENT with a very large calculation domain in order that the flow could be considered unbounded. The investigation covers the power-law index from 0.2 up to 2, the Reynolds number range from 0.1 up to 40 and the Carreau number from 0.1 up to 20. Wake lengths and drag coefficients have been calculated for many combinations of the above three parameters. At low power-law index the wake length changes non-linearly with increasing Reynolds number and as the power-law index rises the variation becomes linear. The drag coefficient reduces in shear-thinning fluids and grows in shear-thickening fluids with increasing Carreau number. At the same Carreau number the drag coefficient is higher is shear-thickening fluids compared to that of shear-thinning fluids.