Flow simulation around square cylinder with inclined corner gap at low Reynolds number

Abstract

In this paper, an investigation of the effects of inclined corner gaps of varying widths and lengths on the static aerodynamic force coefficients and flow features of a square cylinder at low Reynolds number (Re of 100) by comparing with an unmodified square cylinder is discussed. The width of the corner gap (x/D) was varied between 0.02 and 0.24, with two different lengths of it (l/D), namely, 0.05 and 0.11. The open-source code OpenFOAM was used as a solver. A second-order accuracy level was ensured for both time and space during the numerical set up of the model. Validation and verification studies were conducted to ensure the authenticity of the results. The mean and rms values of the static force coefficients of these cylinders were compared and important flow features were explored. Even at a low Re, the proposed corner modification was found to be effective in improving the static aerodynamic performance. For different gap widths, the static force parameters evidenced some patterns, with an optimum width for which the mean drag value reached the minimum value identified. Furthermore, the mean and fluctuating pressure and velocity contour were analyzed to understand the underlying flow mechanism.