Experimental study on the aerodynamic characteristics and wake flow feature of triangular prisms with various round corner radius

Abstract

In this work, particle image velocimetry (PIV) and wind pressure measurements are employed in the wind tunnel to investigate triangular prisms with different rounded corner radius. The effect of rounded corner radius on wind pressure distribution, aerodynamic force, and wake flow characteristics are analyzed. Results indicate that the surface wind pressure can be effectively reduced through filleting treatment, with an average drag coefficient decrease of 52.7% as the corner shape transitions from sharp to round. The continuous increase of the radius of the rounded corner causes an accretion of the fluctuating lift coefficient, and a slow decrease of the drag coefficient. The modification of the corner radius has a limited impact on the vortex shedding frequency, but the shedding vortex tend to gather the leeward side. Additionally, statistical analysis of wake flow shows that an increment in the rounded corner radius leads to a significant reduction in the wake recirculation region, amounting to 20.16%. Concurrently, the peak values of turbulent kinetic energy and Reynolds stress exhibit a pattern of initial increase followed by a decrease. On the other hand, results of proper orthogonal decomposition suggest that the spatial distribution of vortex structures becomes increasingly compact with the enlargement of the rounded corner radius.