Time-periodic non-Newtonian power-law flow across a triangular prism

Abstract

The effects of non-Newtonian power-law fluids on the unsteady unconfined fluid flow characteristics of an equilateral triangular prism are investigated for Reynolds number (Re) ranging from 50 to 150 and power-law index (n) ranging from 0.4 to 1.8. The flow field around a triangular prism is represented by streamline contours. The output parameters such as root-mean-square values of lift and drag coefficients, time-averaged drag and lift coefficients and Strouhal number are calculated. A time-periodic behavior of the flow is observed for the entire range of control parameters studied. An increment in the time-averaged total drag coefficient is observed with the increase in Re for pseudo-plastic and Newtonian fluids. However, for dilatant fluids, a mixed trend is observed when time-averaged total drag coefficient is varied with n. There is an enhancement in the value of Strouhal number with the increase in Re for dilatant fluids, whereas a mixed trend of Strouhal number with Re is noticed for pseudo-plastic fluids.