Numerical investigation of flow past a triangular cylinder at various Reynolds numbers

Abstract

Numerical simulation of flow around a triangular cylinder placed both in left and right position at Reynolds number Re = 80–200 is presented in this study. The single relaxation time lattice Boltzmann method is used. The results are obtained in terms of vorticity contour visualization, drag and lift coefficients, and force statistics. Regular vortex shedding is observed for both cases, but the vortices generated for a triangular cylinder placed in the right position move toward the top downstream position as the range of Reynolds number increases due to effect of pressure (effect of thrust). The drag coefficient is constant, and lift coefficient is containing negative values from Re = 80–150 for that case, but negative Cdmean values are not observed for a triangular cylinder placed in the left position. In that case, it is due to the reason that the effect of thrust diminishes. The maximum value of Cdmean is obtained at Re = 200, that is, 1.5006 for the left triangular cylinder, but the value of the mean drag coefficient for the right triangular cylinder is zero throughout the cases for Re = 80–200. No fluid forces are produced for right triangular case. The Strouhal number (St) values increased by increasing the Reynolds number, i.e., Re = 80–200, for the right triangular cylinder, and it has a mixed trend for the left triangular cylinder. In literature, a lot of work has been found on rectangular and square cylinders, but triangular cylinder has not been studied much.