Flow interference investigation of multi-square prisms under fluid–structure interaction. II. Flow field phenomenology of side-by-side square prisms

Abstract

The current research primarily focuses on interference effects in rigid structures, with the omission of the feedback impact of structural vibration on the flow field preventing the disclosure of the intrinsic mechanisms behind interference effects. Therefore, this study analyzed the aerodynamic characteristics and flow field phenomena of the finite-length side-by-side square prisms under vibration through the large eddy simulation, unveiling the flow field morphology and disturbance mechanisms. The results show that the three-dimensional effect of the side-by-side square prisms effectively suppresses the deflection of the gap flow. Structural vibration increases the curvature of the shear layers on both sides of the interfering structure, weakens its end effect, and destroys the integrity of the axial vortex in the wake region. With the increase in the spacing between the side-by-side square prisms, the “narrow pipe effect” is weakened, the flow acceleration is relatively slowed down, and interference of the vortices in the wake region is weakened. In addition, some typical flow field phenomena are observed, such as gap flow instability, coupled vortex street, interaction of wakes, and different flow regimes. This study is of great significance for understanding mechanisms of the flow interference around the finite-length side-by-side square prisms under fluid–structure interaction.