VIV & Heat Transfer for Flow Around a Square Cylinder with Corner Modifications at Low Re

The flow-induced vibrations and heat transfer properties around a square cylinder with altered corners are examined through numerical analysis to examine thermo-fluid performance. Water is utilized as the working fluid for two-dimensional (2D) simulations at a Reynolds number of 100, for a laminar flow past both sharp and chamfered cornered square cylinders. The study numerically investigates the impact of modifying the chamfer edge sizes and corner cut angles (10°, 20°, 30°, 40°, and 45°) on forced convection heat transfer from a vibrating square cylinder that is suspended elastically. The simulations are carried out with a reduced velocity <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathbf{U}_{\mathbf{red}}=\boldsymbol{6})$</tex>, considering variations in chamfer edge sizes and corner cut angles. The analyses are conducted maintaining constant values of the Prandtl number at 7.1, Reduced mass at 2, and a damping coefficient, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{\xi}=\boldsymbol{0}$</tex>. The findings are presented in terms of the average drag coefficient, fluctuating values of both lift and drag coefficients, the Strouhal number and cylinder's motion trajectories. Additionally, the average Nusselt number, Nu(avg), is shown to highlight the heat transfer features surrounding the square cylinder with modified corners. The study explores the effect of corner modifications on the average drag and vorticity strength predominantly. Average drag decreases for small angular modifications but increases for larger cut angles due to an increase in the shear layer velocity and accompanying large wake recirculation bubble. Average Nusselt number increases to a maximum for the case of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{C}^{*}=\boldsymbol{0.5}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{\theta}=\boldsymbol{45}^{\circ}$</tex>.